A digest of the literature through 1934 relating to insecticidal spray residues

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Title:
A digest of the literature through 1934 relating to insecticidal spray residues
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Busbey, Ruth L ( Ruth Lawless ), 1909-1990
United States -- Bureau of Entomology and Plant Quarantine. -- Division of Insecticide Investigations
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United States Department of Agriculture, Bureau of Entomology and Plant Quarantine, Division of Insecticide Investigations ( Washington, D.C )
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February 19'9


United States Department of Agriculture
Bureau of Entomology and Plant Quarantine


A DIGEST OF THE LITERATURE THROUGH 1934
RELATING TO IPTSECTICIDAL SPRAY RESIDUES

By R. L. Busbey, Division of Insecticide Investigations



Contents

Page
Introduction -------------------------------------------------- 2

,I. Public health aspects of the spray residue problem ----------- 3

II'. Legal aspects of the spray residue problem ------------------- 32

III. Rcmoval of spray residues from fruits and vegetables --------- 59

A. Processes -------------------------------------- 59

B. Apparatus ------- --.--------------------------- 129

IV. Relation of spray progr-mi to residue -------------------------- -138

V. ,Methods of analysis for spr-.y residues ---------------------- 168

A. Arsenic ---------------------------------------------- 168

B. Lead ------------------------------ --------------- 181

C. Fluorine, sulphur, copper, spray oils, etc ---------- 188

VI. Results of analyses of spr-yed fruits and vc-tables --------- 191

VII. General -nd unclassified articles on the spray residue problem 210


E- 463







. -2-


INTRODUCTION

The purpose of this publication is to bring together references to
the numerous articles relating to insecticidal spray residues that have
appeared in the last ten years. A voluminous literature on this subject
now exists, a literature that is widely scattered through horticultural,
entomological, medical, chemical, and legal publications as well as in
annual reports, bulletins, and circulars of State and Federal agricultural
experiment stations.

In spite of the advances that have been made since 1926 in methods
and apparatus for removing spray residues of lead arsenate and other in-
secticides from apples, improvements in both processes and machinery designed
for washing fruits and vegetables are possible. Since progress can be
made only when a knowledge is had of what has been done, this digest should
prove useful to researchers in this field.

At present the United States Department of Agriculture tolerances for
insecticidal residues on fruits are as follows:

Grain per pound

Arsenic (expressed as As20O) 0.01
Lead (expressed as Pb) ....... ,................. 0025
Fluorine (expressed as F) ......................... 0.02 '

To facilitate finding information in this compilation it has
been arranged in parts which group articles dealing with the various
phases of the subject. Author and subject indexes are provided in which
reference is made to publications by numbers,

References to articles in this digest were obtained chiefly from
the following abstract journals: Chemical Abstracts, 1907-1934 inclusive;
Agricultural Index, 1917-1934 inclusive; Experiment Station Record, through
volume 70, 1934; Review of Applied Entomology, Series A, 1913-1933 inclu-
sive; Chemisches Zentralblatt, 1926-1932, inclusive; Index of American
Economic Entomology, volumes I to IV; and the card index of Miss Mabel
Colcord, Librarian, Bureau of Entomology and Plant Quarantine.







-3-


I. PUBLIC HEALTH ASPECTS OF THE SPRAY R]SIDU2 PROBLEMvi

ANONYMOUS (1)

I SALI DI ARSENICO IN VITICOLTURA SD IN AGRICOLTURA. Rivista di
Agricoltura [Parnm]j 19: 499. 1913.

In products derived from plants treated with arsenical
compositions, arsenic is often found, generally in minimum doses but
often up to 2 mg. per kg. of fruit and 1 mg. per liter of wine.
These quantities of poison are harmless when considered by
themselves, but when the greater part of one's food is in the
above-mentioned condition, the daily use of such food would pro-
duce slow and unavoidable chronic poisoning.

(2)

L'IIPIEGO DEGLI INSETTICIDI ARSENICALI Z I SUOI PERICOLI
IGIENICI. Minervr Agraria 7 (5-7): 93. 1915. Translated from
Arb. a. d. Kais. Gesundheitsamte 29: 11. 1915.

(3)

DAMAGING PRESS PUBLICITY. Fed. Brit. Growers Jour. 2: 181-182.
1923.

Two newspaper articles reporting the warning of a
scientist concerning dangerous amounts of arsenic and copper
sulphate on sprayed fruits, and a letter written to the editors
of the papers by the secretary of the Federation of British
Growers, denying the truth of the statement, are quoted. Readers
are urged to report immediately any such adverse publicity
appearing in newspapers, so that it may be replied to promptly.

(4)

DANGER OF ARSENIC IN CLOTHING. Jour. Amer. Med. Assoc.
80: 1072. 1923.

An arsenical solution containing the equivalent of
0.05 percent arsenic pentoxide has been advertised as a larvi-
cidal spray for the moth-proofing of clothing. Pollution of
the air when the clothing is brushed, poisoning of infants by
sucking treated woolens, and the development of skin rashes
due to contact with treated under clothing are dangerous possi-
bilities. It is hoped that dealers in wool clothing will not
be parties to the distribution of this potent poison.

...- (5)

ARSEIC IN APPLES. Lit. Dig. 88 (8): 26. 1926.


This statement is based on an article in The Lancet








deploring the use of lead arsenate on fruit trees and point-
ing out the danger'of poisoning by the residuial arsenic on
the fruit.

(6)

POIS01]IiG BY iRSENICAL SPRAYS. Amer. Jour. Pub. Health 1S: 403.
1926.

An editorial discussing cases of arsenical poisoning in
England.which were traced to the eating of American apples.

(7)

THE ARSENIC SCARE. Citrus Leaves 6 (2): 30. 1926.

Considerable undesirable publicity on American apples
has gotten across to British consumers, and therefore harm has
been done to the applu export business because of the associca-
tion of illness with the eating of apples coated with arsenical
spray residue.

(8)

PFLANZENSCHUTZ UND BIENENSCHUTZ. Vortragsreihe des Reichsaus-
schusses fur Bienenzucht. 32.pp. n kklm. 1931.

Includes: K. H. Kickhoffel, Plant protection and apicul-
ture; H. 1Liorstatt, The necessity for poisons in plant protection;
A-Borchert, The effect of poisonous insecticides on bees; Hil-
gendorff, The determination of arsenic in bees; W. Troppmann, The
use of poisons for combating pests of orchards, vines, and field
crops; M. Voelkel, The use of poisons against forest pests; H.
Gotze, The dangers to apiculture of the use of poisonous i.isecti-
cides.

(9)

POISONOUS Ii`SECTICIDES jIJD PLANT SPRLYS. Jour. Amer. Moed.
Assoc. 101: 126-127. 1933.

An editorial. A symposium on insecticides appearing in
Industrial and Engineering Chemistry [25: 616. 1933 ] is dis-
cussed. Farmers and fruit growers insist there is no danger
from lead and arsenic as used on fruits. They do not appreciate
the danger of cumulative chronic poisoning. The user should
thoroughly wash and cleanse fruits and vegetables before putting
them on the table either raw or cooked, and perhaps should strip
the outer layers from lettuce, cabbage, and similar vegetables.

S(10)

GIRL DIES, 2 iZDE ILL BY INSECTICIDE. Phila. Record. July 17,
1934.





-5-

The death of a 3 year old girl and the serious illness
of two companions is reported as caused by eating beans which
had been sprayed with arsenate of lead to kill Japanese beetles.

S--- *..(11)

SCIZITISTS HUNT NEW WAYS TO KILL `ZRi.S. Better Fruit 29 (10): 4-5.
1935.

Because of the great interest in the health aspect of the
use of lead arsenate on apples and pears, the problem of codling
moth control has become difficult. Federal and State horticul-
turists have developed machinery and solutions for removing poi-
sonous residues.

AMBRUSTER, H. W. (12)

THE PROBLEM OF ARSENICAL SPRY RESIDUE. Jour. Franklin Inst.
206: 597-604. 1928.

A brief history and discussion of the spray residue
problem. This is primarily a problem which must be settled
first in terms of toxicology and physiology and all other phases
of it worked out from a basis of standards set by those sciences.

ANDREW, R. L. (13)

ARSENIC IN NEWV1-ZE.JLAiD-GROWN iAPLES. New Zealand Jour. Sci.
and Tech. 9: 206-209. 1927.

Although the minimum medicinal dose of arsenic is 1/32
grain, quantities as low as 1/40 grain may cause symptoms of
poisoning in susceptibles persons.

Results of analyses on sprayed apples show that with
ordinary spraying practice, and provided there is an interval
of 12 to 15 days between the last spraying and picking, there
is no risk of the arsenic being in excess of 1/100 grain per
pound.

Wiping is probably of no value for removing arsenic
except when patches of dry spry are visible on the fruit.

APP, F. (14)

SPRAY RESIDUES. Amer. JAgr. 131 (19): 6, 27. 1934.

An article on sprpy residues appearing in the Philadel-
phia Inquirer on august 19, 1934, is criticized as giving the
impression to the hasty reader that all fruits and vegetables
are dangerous. iviost vegetables are trimmed and washed by the
producer, making it practically impossible to carry residue to
the consumer's table.






-6- '

3E.IJERS, j. A.: (15)

KOPERVERGIFTIGIITG BIJ SdHAPiEN. Tijdschr. Diergeneesk.
59: 1317-1324. 1932. [English summary.]

The author describes a few cases of chronic copper-
poisoning in sheep which had been grazing in orchards sprayed
with a solution of copper sulphate.

BOAZ, V. T. (16)

THESE APPLE PZELIYGS AGAIN. Better Fruit 28 (2): 8-9. 1933.

A satirical editorial making light of the alleged dan-
gers of spray residues and, in effect, criticizing the policy
of the United States Department of Agriculture of not comment-
ing on the merits of insecticides marketed under proprietary
names,

BORCHERT (17)

UlITEj-SUCHUIG UBER DIE GIFTWIRKLJ-G KUPFEPHALTIGER VEB3IKDUMG
BEI. DEN BEIENK. Berl. Tierartz. Wchnschr. 1: 84. 1930.
[Abstract in Rev. Appl. Mycol. 9: 664-665. 1930.]

Bees in lots of 100 were fed on copper-containing
plant protectivos, copper sulfate and basic copper carbonate
(plus powdered sugar and honey water) in varying concentration,
and a concentration at which 25 percent of the insects were killed
was determined. The toxic dose of 5 copper-containing fungicides
was 8.8 micrograns of metallic copper, and the figures for the
other copper compounds were approximately the same. These
disinfectants being naturally bitter and not as a rule arti-
ficially sweetened, the d-anger to bees from their use may be
considered negligible.

BRODSKII, I. (18)

THE TOXICITY OF ACID COPPER CAMBO. iATE SPRAYS ON THE ANlIiAL
ORGAiIISiVL. Arch. Gewerbepath. Gtwverbebyg. 5: 91-107.
1933. [In German.]

CAZE1EUVE, P. (19)

LE DANGER DE L'IITTOXIC.TION KRS&NICILE ET PLOiJIQUE EN
AGRICULTMLE. Rev. Vitic. 41: 29-34. 1914.

Lead arsena-te should not be used c.s-anz agricultural
insecticide because of the danger to the health of those em-
ploying it and those consuming the products so trer.ted. Ex-
amples of illness due to its use are givun.






-7-


------- (20)

FATAL INTOXICATIONS BY ,kSZNIC IH VITICULTUP.L DISTRICTS.
Bul. Acad. ;,Led. '[Paris] 85: 660-671. 1921. [In French.]

CH.,PELLIER, A., and RULtCOURT, M. (21)

LA TOXICITY Z1VWE.S LE GiBIzR DES INSECTICIDES ARSENIC.AUX.
Compt. Rend. Acad. Agr. Fr:nce 20: 598-603. 1934.

The toxicity of sever:,i scrsnical insecticides to the
rabbit and. .are was studied aa.d the followLrn conclusions Vweore
rec.ched:

1. Diplumbic arsenate is the least d..ngorous of the
insoluble arsenicals employed as insecticides.

2. Paris green is the most toxic, at least 6 times more
so than lead arsenate.

3. Tricalcium arsenate and aluminum arsenate have an
intermedir-.te toxicity.

4. The ropeo-ted absorption of quantities of poison
distinctly lower thrjn the fatal doses did not appear to be able
to provoke slow intoxications.

HOTY, R. (22)

THE DGE?. OF TIHE USE OF aRS-iJC C0iPOU-NDS Ih VITICULTURE.
Ann. Hyg. Publ. Indus. Sociele 1930: 303-304. [In French.3

CL.iJXE, J. 0. (23)

ThE SPR.-.Y Pz-SIDUE PP,03LZL. Kans. State Hort. Soc. Bien.
Rpt. 40: 69-77. 1930.

Lead and arsenic spr.:?y residues are discussed from the
point of viw,1 of public health. Re commendations for washing
fruit with hydrochloric acid cre based on U. S. Deot. ;gr.
Bull. 59.

CLOVES, Z. S. (24)

POISC I!; Sv .fLL DOSES; H0Oi ThE CILMrIC.L '{a2, AGAINST Ii;SECTS
AFFZCTS OUR FOOD SUPPLY. Hygeia 5: 4S-461. Illus. 1927.

It is highly probable that every person v/iho e.ats a fair-
ly wide diet, including especially fresh fruits and vegetables,
and who does not take sornme pains to see that they are carefully
washed before eating, swallows a measurable amonur.t of arsenic
ad lead every dcay, an amount far below any dosage likely to
cause symptoms of illness but the ultimate effects of which may








be serious. Fruit should always be peeled or washed or wiped
thoroughly, especially if a gray residue is visible on its sur-
face. Vegetables such &s celery and lettuce should be thoroughly
washe d.

All competent authorities agree that there is nothing in
the situation to be alarmed about. Fruit and vegetables are
good foods and nobody is known to have been even made seriously
ill from eating them. Furthermore, the growers are alarmed at the
reaction already resulting from the action of health authorities
end are taking all precautions to rid their products of the last
traces of poison.

cCX, H. E. (25'

THE OCCU.i:CE OF ARSENIC IN APPLES. Analyst 51: 132-137.
1926.

Two cases of poisoning were reported in Hampstead and
suspicion fell on certain imported Jonathan apples. These were
found to contain 8 parts per million of arsenic as arsenious
oxide and 28 parts per million: of lod. Of 39 samyles of Ameri-
can apples ex-mincd, only 5 were free of arsenic. There could
be no reasonable doubt that the presence of the arsenic was due
to the use of arsenates as insecticides for spraying the fruit.

DAHIiER, G., and iwEYER, H. (26'

UINTERSUCHUNGEN lBEi. DEI1 ARSE1I- UtD BLEIGEH-LT AN 0BST li GEFOLGE
DER SHADLIIIGSBEKAiLPTIFUKG. Geisenheimer Mitt. 43 (1): 3-8.
1928. [Abstract in Zentbl. gosamte Hyg. u. Grcnzgebiete
17: 346-347. 1928.]

The arsenic and lead content of apples, grapes, and cur-
rants treated with "Nosprasen" (a leac.d arsenate preparation)
and lead arsenate, and of currant marmalade, jelly, etc., are
given in tables. Special attention is devoted to the amount of
fruit wiaich would cause harm if eaten. Lead, in contrast with
arsenic, is a cumulative poison. Repeated consumption of amounts
of arsenic u-der 0.03 grain ceuse no harm to man, but amount of
about 0.004 grain of lead ingested with fruit daily for months lead
to chronic lead poisoning. Especially injurious is the consump-
tion of currant marmalade made from fruit growing in orchards,
and strndinig under trees treated with lead arsenate. Even when
the currants are ';ashed before use, the lead content is still
quite consider!.bl. and there is the possibility of the daily con-
sumption of about 350 grain or more,' leading to lead poisoning.

DAVIS, J. J., et al. (27

[SPRAY RESIDUE REi0VAL.] Ind. State Hort. Soc. Trans. 72: 31-32.
L933.


* S-*8





-.9-


There is an increasing sentiment on the part of the pub-
lic against fruit and vegetables, sprayed with arsenicals.
Studies are being made toward tLe development of effective and
practical non-arsenical sprays.

DE EDS, F. (28)

CHR61,TIC FLU0IOI!.r I ,TOXCATIO:. ;eC2iclne 12: 1-60. 1933.

The distribution of fluorine is so widespread that a
small intake of the element is pract.celly unavoidble. A
daily intake of 0.1 to 0.3.5 rg, of fluorine per kg. of body
weight is capable of producing at least one important mani-
festation of chronic poisoning, i. e., mottled teeth. Therefore
the use of fluorine compounds as insecticides or fumigants for
plants or foods should be limited to conditions .ah-re satisfactory
removal of fluorine residues can be carried oat before placing
the food on the market. Chemicl P-nalysos should be made on a wide
variety of foods gro-.,n an(. p01: re',Q u-.der corditions where the
fluorine content is acquired solely through naturj3 processes,
and on the basir of these analrcses a Tolr--nce limit for added
fluorine Fhould be specified. A bibliojr.-i'y of 128 references
is given.

----- (29)

C0C1 PAk:TIVE TCXIC7 I'7, WITH SP.CITL ;-'P.E2i. TO ;.:i-CAL
FLTD FL.JCRIT-C~irITh.::u I-:SCTI2I S. Jour. Zionr. Ent.
26: 302-304. 19S3.

Recent investigation has shown that a definite abnorm2l-
ity of the teeth mry be produced in e;: 3riacnt.l rats by concen-
trations of fluorine which do not retard growth. S.yth an,
Sayth, using this as an index of toxicity, conclude that arseni-
cal compounds are several times moro toxic than fluorine insec-
ticides. In viev of the wide variation in different species
in suac,:ptibility to toxicity of a given agent end in view of
the extremely low concentration of fluorine in the drinking
water at St. David, Ariz., Cn endemic area for mottled teeth,
it would not be surprising to find eventually thaLt in men the
margin of safety for fluorine insecticides is no greater than
for arsenical nrateriels. Until the lowest possible- threshold
toleranc- for fluorine compounds has been. esttablished in sever-
al species, an.n until the fullest use has been made of informa-
tion to be gleaned from areE.s where mottling of teeth is ond-rric,
the question of the wisdom cf substituting fluorine-containing
insecticides for lead arsenate must rem;.dn an open orne.

DEGRULLY, L. (30)

PktCAUTIOS I ?PRDR EPCLR LIZ,.PL0I LES ARSOICAUX. Progres
Agr. et Vitic. 78: 46'-4u5. 1922.





-10-


Lec-ves wl-ic have urwcergone a trcat:,ent with prsenical
products should not be used to wrap any ePliretarvy substance.
They should not be used.,. in eay case, as foci for live-stock.

ECsCHEluci, E. E(31)

ZUR AESTi:;FRILCE. GE I JJXIN BLN SCHPruimE DZR VE.5.,kND LSEiJ :-
HALTIGER MITTEL I i ,ILBAL. Ztschr. Angew. r-nt. 8: 185-187.
1921.

Several authorities are quoted. on the question of the
use of arsenicals in viiineyvxrd. The fecr of poisoning from
this source is e.ragerated.

SVATS, T. V. (32)

ArS.:1IO PI0lG 0S0 PR-IM ZP IL YE P A3P.L:SJS. Jour. Amer. ,vied.
Assoc. 99: <2')2-2L03. 193 .

rrA nmmbor of j-omen who pttr.r.dd a dinnrnr '.-here fresh aS.s ara-
gus was served were tx:c-n v1iolently ill with symptoms suggesting
arsenic posioning. T-vo b(.chIs of hee aspEr.-yus used ve're ann-
lyzd. z.nd ons was found to co,.tin a little wrsnic, while the
other contained. '.rsnic much in excess of the amount tolerated
by the pure food lavs.

FAES, lH., TOG:DUZ, P., PIGUIE, G., and S2O-CH{ELI, L. (33)

LES SZLS .ESi:IC N ABILTULE. Sun. Asr.Siss 24: 315-338.
1923.

;-rs,-nic compounds are dangsouz V.bCorxtive Ioijonz. Ar-
senical treatrLents of vegt-bles s.iould bL: carried out very early
so that a consiier:obl. interval separates the time of treatment
from the time of consumption. Experiments carried out a.rLnct the
apple worm show that the quar-tity of arsenic remair.L_- at .harv st
on the skin of the trecAte& fruits is very sirll fromi less than
O.O0C1 to 0.01 mg. per 10 g. of skins] and cannot exert an unf.vor-
able action on the human oran.-sr;. ThE flesh of the tre-z taed fruits
contains only negligible tr..ce.j of arsenic.

FAGAN, F. N. (34)

WHAT IS THE iY TO RE:.OV P.Y SLT NS FL S.PLZS.
Pen-i. State Hort. Assoc. ?roc. 1923, 64th Arir. Meeting, p. 41.

The perfecticn of sprc:.ders and stic':.rs may mean
the ca.rryin, of a.-re spray ma.terircL on the ruit into trie
market, There may be objections to tids from the poirt of
vicvw of public health. The author believes r-.yoie vwnuld
die from the effects of over-eati. P before th,.,y ;ot cno'lng'
arsenic to hurt them. Oome growers brush or ie t fruit
to remove the sprny steins.





11--


FIZtiRitG, T. VON (t)

tBER. DEN Ad.SL-GE7ALTT IUAIURLI EI2 T-D ,IT A. TPjI-?TTEIJ
B-'.h:DsLLU. L:.iTTEL. iochlem. Ztschr. 218: 300-317.
1930.

The author's results indicate that fruits 3prc-r with
arsenic could scarcely c!u..se aroei'c poisoning. On the other
hand, lead arsenate should be discarded becarise of its lead content
and should be replaced by other arsenic preparations, such as
calcium ar2senate.

C. H. (36)

[REPORT OF] DIVISION O ETTO,,CLOC-Y. ,Aass. [Hatch] Agr.
E:,pt. Sta. Bull. 2, pp. 3-!C. 1883,

From 1 to 2 Erains of arsenious acid will probably
prove fatal to an a-Lult p.rson. TIe Lot:, dose of paris green
would be 2 to 3 times th;,, ard thLt of Icndnn purple about
the so-me as paris jre:-n. ?Fitsis, followed oy milk and eggs
or cuT>-.r and ,ni.-reoia in iilk, is recornmendec. for trec tment
of arsunic:1 poi5n-mn.

FERRI, L. (37)

LA ITICOTINE EN VITICLTTUP2. Ann. Falsif. 23: 337-344. 1930.
Rev. Vit. 73: 178-184. 1930.

The use of nicotine in viticulture presents no
inconvenience since it is alw-ys completely eliminated no
matter %v.h-t the at-qospheric conditions n,,,y oco. In rainy years
it is carried off because of its solubility in water. In dry,
.iarm years it volatilizes. TL., same c-.nnot be said of the
arseniceals usually r;o-d.

FISHER, D. F. (38)

C ViT EVLOPiKliTS IN SPRAY F.JSI'd-. P-iOVAL. Jour. iEcon. Ent.
2-1: 526-529. 1931.

The psychological aspects of spr;-, residue removal,
rather the-n attend,-,,t technical difficulties, are the factors
which need greatest emph-.sis at the present time.

FRACOIS, L. (39)

LES COiJPOSES DE L'ASS1:IC ET LA MISTRJCTI0 DES PA.ASIT2S.
Rev. Chim. Indus. 23: 124-131. 1912.

The use of arsenical insecticides on grape vines and
fruit trees does not lead to dangerous' aminounts of arsenic on
the mature fruit or in wine or cider -nmade from it. The absolute






-12-


interdiction by the French Government of the use of arsenicals in
agriculture is protested.

GA"IMAi, H. (40)

INSECTS INJURIOUS TO CABBAGE. Ky. Agr. Expt. Sta.
Bul. 114. 17 pp. 1904.

Two cases of illness.attributed to eating cabbage
containing arsenical spra,; residue are reported.

GATES, B. N. (41)

SPRAYING VERSUS BEEKEEPING. Mass. State Bd. Air.
Apiary Insp. Bull. 10A. 22 pp. 1916.

Reports are quoted and discussed from various parts
of the country on poisoning of bees because of the applica-
tion of insecticidal sprays to fruit tr3es while in blossom.

GOSSARD, H. A. (42)

IS SPRAYING DANGEROUS? Ohio Farmer 139: 554. 1917.

There is less danger to the consumers of sprayed
products, on the average, than to the consumers of unsprayed
fruits and vegetables which because of the presence of rots,
fungous diseases, aid accompanying deleterious products of
decay, are a greater threat to human health than sprayed
sound fruits and vegetables with scarcely more than a trace
of poison on them. The author cannot recall a single proved
case of death due to eating spra-yed products. If products
have been heavily sprayed with bordeaux mixture so that much
adheres at harvest, washing with water with vinegar added will
remove it. If an orchard wvre heavily sprayed at the season
when such crops as lettuce, spinach, beans, or heading cauliflower,
growing between the rows, wore about ready for harvest, too much
poison would likely adhere to the leaves. Spraying with
arsenate of lead can be performed on raspberries and black-
berries until the most forward fruits are one-third to one-
half gro'n.

GWIN 0. M. (43)

THE PAST AND PRESEiJT STATUS OF FLUORII.E COi.TAI. ING flSECTICIDES.
Jour. Econ. nr.t. 26: 996-997. 1933.

During 1932 there appeared several- publications by
Smyth and Lei.tz and by Sriyth, Lantz, and Smyth covering the
chronic off ects of fluorirne. For a short time their data
brought about a sli-it curtailment in research with the
salts of fluorine as insecticides.








-13-


HARDING, T. S. (44)

H0W MUCH POISOiA C'2T nU ZAI? Sci. Amer. 149: 197-199. Illus. 1933.

A popular discussion of the apray residue problem.

"It is very strange how sone of us become frightened
at shadows. ThousEands become alr.ost too scared to eat anything,
while the fussy fanatics who write sensational books profit
well in a monetary '.'a and pose in self adulation as saviors
of menekind and c1-_mrpions of the downtrodden public."

EZArTY, E. W. J. (45)

ARSENIC SCARE IN Z'.TGL.,D. Y. Y. State Hort. Soc. Proc. 71: 201-
202. 1926.

Because of illness alledgodly caused by eating apples
containing an a-ecase of arsenic, certain retailers were
arrested in Znelcnri. for having on sale apples containing in
excess of 0.01 grain of arsenic [arsenic trioxide] per
pound. Widespread publicity has made this matter a real
issue.

HC, G. H. (46)

HOW CLIFORiUI.. 1.i2T SPILiY DIL,".LC. Setter Fruit 21 (7): 7. 1927.

All fruit, including pea.rs, shipped from California during
thO. current ye-.r 'were wiped to remove arsenical residue. The
incongruous situation in the United States Dcpartr.iCnt of
Agriculture, where the Burecau of Entomology has recommended
the use of lead arson:.te sprrys for the codling' moth and the
Bureau of Chumistry has declared the fruit so trea-ted to
contain excessive lead and arser.ic and to be deleterious to
human health, is corrm,.ierntd on.

HiNGL, F., RECKZIDORFER, R., rnd BEPIi, F. (47)

DER ARSEI.- UI.D BLEIGE2iLT VOCl TPUBEiJ, TPWL-Zl.,OST "JNTD -.lE:
[IS FOLGE DER SCH -DLIIGSB'iPFUlIG. Gartenbauwviss. 4: 38-51.
1930.

The -rou-.t of arsonic found on gropes five weeks after
the last treatment with lead arsenate is so small that musts
and wines prepared from them would cause no harm wore it not
for the presence of lead. Grap.s for eating, taken from arsenic-
treated vineyards, should, howev-r, be 7w-shed. The %nount of
lead remaining on grapes five weeks after tre-.tment is still so
high that even a sm.ll amou-t could cause harm. The use of lead
in bearing vineyards should be entirely forbidden.








HERMAiI, F. A., and BRITTItIN, W. H.


APPLE PCLILI1IATI01 STUDIES. V. STUDIES IN BEE POISO11I.G AS A PHASE
OF THE ORCHARD POLLIITATION STUDIES. Canada Dept. Agr.
Bull. 162: 158-193. 1933.

Sprays and dusts containing arsenicals are dangerous
to bees when applied during bloom.

HILGEJIDORFF, G., and B3RCHERT, A. (49)

UBER DIE EMPFINDLICHKEIT DER BIENET GEGEN ARSEIUSTAUBFaiITTEL.
Nachrichtenbl. deutschen Pflanzenschutzdienst 6: 37-38. 1926.

Results show that the death of bees and dusting with
poisons are closely connected.

HUTSOW, R. (50)

BEE IIVESTIGATIOT. N. J. Agr. Expt. Sta. Anr. Rpt. 1923-1924,
pp. 325-349. 1925.

The bees in a certain apiary were very low in stores when
the petal-fall spray was applied at the experiment station about
three-eighths of a mile away, on :'aLy 20 and 21. On May 23 two hives
of the bees exhibited symptoms of "disappearing disease". Arsenic
was found in excess of 0.0002 mg. per bee. Subsequently, 500
mg. of arsenic trioxide was administered to a shook swarm ohich
built combs from syrup containing the arsenic. Nothing happened,
although 500 mg. is enough to kill 2,500,000 bees, a number equal
to 40 to 50 ordinary hives, supposing the minimum lethal dose
for a bee wore 0.0002 mg.

KALKUS, J. wv. (51)

ORCHARD HORSE DISEASE. Amer. Jour. Vet. Med. 15: 139-144. 1920.

A disease found in horses grazing in sprayed orchards or
fed on orchard hay is described. Some authorities believe that
this is due to lead arsenate poisoning.

BALLET, A., and SOCHLII:K, F. J. (52)

100,000,000 GUII:EA PIGS. 312 pp. "lew York. 1933. Nation
135: 325-327. 1932.

In chapter III, entitled "A steady diet of arsenic .nd
leadtd", the danger to the public health of arsenic and loed
residues on fruits and vegetables is discussed. The results
of lead and arsenic analyses on American apples made by
K. Lendrich are cited, as well as the findings of C. N.
IVfyers end B. Throne as to the prevalence of arsenic poisoning
and its sources. The U. S. Dop.rtmient of Agriculture is


(48)







- 15 -


Criticized for not adopting a more aggressive policy toward the
-elimination of qrscnic and 1 ad spray residui&s. '

%i^AS, H, G, H., and WALTOC", C. L. (53)

A NOTE ON T3 COiiIR'L OF THE EASF53ERY BFETLZ (BYTURJS 2E I. SUS
F*.R.) BY UE-,.TS OF A EAP, IJ SILICFLUC'BRIDE .UASH. Jour. Pool.
Hort. Sci. 11 (I): 77-80. 1933.

Because of the excessive poisonous rcsiduc remaining on
rs.s;borri:s treated with lead arsenate, experiments have been
mLiade with various non-poisonous preparations. The. chronic
toxicity to warm-blooded animals of barium silicofluoride is only
one-twelfth that of lead arsenate and th-refore the health hazard
is probably reduced to a negligible risk.

iLVI'/, ,., DY:E, W. H., CHUICH, W. S., THORPE, T. E. (54)
-0 0SOR, -. C., and THITTLIJWE, B. A.

FINAL tEPOI-T CF THE ROYAL CO::MISSIOD APPOI:T:-D TO I ZUI -7 I7TO
ARSEY!ICAL POI.T0i^Iin- 'Oi ?i{E CONS<.2TI'l- OF BEER AND C-Th.R
ARTICLES OF F30 OR 0 lFi7E. 52 pp. London. 1903.

After an exhaustive inquiry into the subject of arsenical
poisoning from b;:cr or other articles of food or drink, it is
recor.mnended that penalties be imposed upon the vendor of any food
containing nore than 1/100 grain of arsenic [i.e., arsenic trioxide]
per gallon if liquid or more than 1/100 grain of arsenic per pound
if solid.

K} I EG (55)

.ZIT G3E ZUR VERWE:DL&.17 ]2S BLEI-RSEUTIATS IN DEUTS?-HL'J:D.
Verh. Deut. g.-csll. Ar,--:v. Ent., 7. Mitgliedcrvcr>.rx.l.
I.inchen, 31. Mai bis 2. juni, 1928. pp. 101-103. 1j29.

In spite of the '"idespretad use of lead arsenate abroad [i.e.,
outside of Germany], illnesses therefrom remain almost unrkn-'in.
Then Englind.uridertakes an investigation of the lead [?] on imported
fruit, it is done as an economic protective measure for the frait
growers of England and her dominions. The hygienic considerations
are only a pretext.

:;iH.I, H. A. (56)

THE' PFROBLEI.. OF AF.S7YICAL FSILES: IPORTA:E OF SPFY DEPOSITS FROM
THE ST.YDPOINT OF PUBLIC HEALTH. 4th Internal. Congr. Ent., Ithaca,
Aug. 1920. Vol. II, Trans., pp. 673-674. 1929.

Only an abstract of the address is given. The minimum lethal
dose of a number of insecticides, including arsenious oxide, calcium






- 16 -


arsenate, load arsenate, barium fluoride, and sodium fluosilicate, ad-
minirstered by mouth to warm-blooded animals, was determined, The re-
sults obtained were: arsenious oxide, particle size 10.5 mu, 20 mg, per
kg. body weight for rabbits and 85 mg. per kg. for dogs; calcium arsenite
(consisting of 46.8 percent calcium arsenite, 6.8 percent calcium arsenate
and 45.8 percent arsenious oxide), 8 mi. per kg. body weight for dogs;
calcium arsenate (70.5 percent Ca3(AsO4), with an excess of calcium oxide
and approximately 0.2 percent water-soluble arsenic calculated as As205),
38 mg. per kg. for dogs and 50 mg. per kg. for rabbits; commercial lead
arsenate, chiefly PbHAs0O, 500 mg. per kg. for dogs; sodium fluosilicate
(74.2 percent Na2SiF0), 138 mg. per kg. for rabbits and 150 mg. per kg.
for dogs; barium fluoride (99.1 percent BaF2), 200 mg. per kg. for rabbits
and 550 rig. per kg. for dogs.

All of the arsenical compounds produced gastro-intestinal irrita-
tion and the symptoms and pathological findings were those of acute
arsenical poisoning. The principal symptoms observed in the case of the
fluorides were those of acute irritation with hemorrhages in the stomach
mucosa and intestines. The principal organs affected were the liver and
kian'%y-.

The toxicity of calcium arsenite when given byImouth is very close
to thrt of arsenious oxide when administered intravenously. The effect
of sublethal doses of calcium arsenate may be chronic arsenical poisoning.
The principal effect of small doses of fluoride will be. loss of appetite,
disturbance of digestion, and of calcium balance.

In order to study the cumulative effect of sublethal doses of lead
arsenate, 4 dogs were given 1/25 of the lethal dose by mouth each 48 hours
The first dog died after receiving 5/25 of the minimum lethal dose, the
second after 11/25, the third after 20/25, and the fourth after 23/25.
All of the dogs developed anemia, bloody diarrhea, and after the fourth
dose showed salivation and nasal discharge such as are usually found in
subacute arsenical poisoning.

The drop in the red blood count was about 30 percent. The principal
organs were analyzed for lead and arsenic. The lead to arsenic ratio in
the dog dying after 47 days is of particular interest. In the original
compound the ratio of arsenic to lead was 1:3.85. At death it was found
to be 1:39.5 in the liver, 1:19.1 in the kidneys, 1:8.9 in the leg bones,.
and 1:5.6 in the spleen. Apparently the lead was being retained while the
arsenic was eliminated.

It is evident that acute deaths from lead arsenate are due essen-
tially to arsenic while in chronic poisoning the symptoms are due princi-.
pally to lead. In investigating the spray residue on fruit sprayed with
lead arsenate, both the arsenic and lead should be determined. The small
amount of arsenic in a spray residue will probably do less harm than the
lead, due to a very slow elimination of the latter,






- 17 -


LARIS0iT, C. .., 2TIC;-:LS, H. E., CARTER, E. A., and WThLLIA:S, C. (57)

[POFT OF SLTJ7 IO:S COI.x- E (PmRTAII-i'!G TO SPIAY ESILUZ).
lvoa State Hort. Soc. !rcas. 67: 105-108. 1932.

The danger of arsenical insecticides froi. tA -taidpoJ-:t of
halth_ is discussed. Dr. Binford Throne is quoted '.s syi. thr't
"_rscnic oven in smaller amounts than the le-al toli.r.ace is a .Oncce
tq -ublic health and from a regulative point of vi-v; the linit set is
.-b surd."

LEDOUX, (58)
IlTOXICATIOF AESEITICAL2 F.:ILIA P'AR LE ViT ZE PALSISIS TRAIS PAR
DES I.SECICISS A DAS S'ASEIATE DE PLOILB. Bu-al. ct iclm. Soc. i.ed.
Ho:itaux de Paris (3) 50: 1566-15C7. 1926.

Five members of a family were -poisoned by drinking wine contain-
inj arsenic due to insecticidal treatment of the Lr,-9es.

tE A:-, H. e(53)

D AlL r... Schweiz. 0Obst. u. Gartenbau-Ztg. 1923 (19): 320-
322. 1923. [Abstract in Rev. Appi. Ent. (A) 12: 45. 1924.1
@
The results from numerous experiments to determine the residual
quantities of arsenic after spraying are tabulated, and the conclusion
is reached that no fear need be entertained of poisoning from this ca-use.

LEi.DIC, K., and :IAY2R, F. (60)

L'B-R DAS VC".:.:0:" VOi? ARSUi? -D U ,LI1 AUF OBST ALS FOLGE bZR
SC:.L:,_iGS5::,:PFIU.:G. Ztschr. Untersuch. Lebensmtl. 52: 441-
457. 1926.

Tests for arsenic and lead were made on fresh fruits, dried
fits, and pr'ese.rves. The preserves, of American origin, yo re
free fron arsenic and lead. The maximum ..iount of arsenic found
in dried appl-s was 0.015 ng. of arsenic trioxide in 100 g.
Fifteen tests were made on fresh apples from the United States,
Canada, and Australia. 7ith one exception, all samples contained
arsenic and 10 contained lead also. T.i.: amtounts of arsenic tri-
*oxio.in the test s -rcoles of 2 or 3 apples y:ore: pulp 0 to 0.029
rg., peel 0 to 2.32 iag., blossom and stem ends 0 to 2.75 mg. The
maximum quantities of la;.d wor. : pool 3.64 mg., whole apple 7.45
ri. (in o5 g. of a.pples). Wishing the apples removes some, but
not all, of the arsenic and lead.

Although in general there nay appear to be no direct
danger to human hec.lth fro-i the amounts of lead and arsenic on
fruit which has received insecticidal treatments, yet in some
c.ases amounts have bean found which cannot be considered har.l ess.






- 18 -


The occurrence of lead. with arsenic seems especially risky since
the foriicr is not eliminated from the huiLian organism as arsenic
is. It viould not be prac'ticablo to try to control the amount
on fruits nor to forbid the use of load and arsenic containing
insecticides until a harmless substitute is found. Pooling
can apply only to apples and pears and not to other sorts of
fruit which are similarly spayed, an.l washing will not be
satisfactory in all circumstances. We would see an improvement
if lead were cut out of the sprays and spraying of fruit trees
and bushes was undertaken only once shortly after blooming.
The elimination of lead seems possible since calcium arsenate
is as active as lead arsenate in insect control. Furthermore
the single spraying would bring about a naked decrease in the
ayoount of arsenic on the fruit.

I.UARD, W. V.s (61)

2:.iOVAL OF SPRAY RESIDUTE. Idaho State Hort. Assoc. Proc. 37: 90.
1932.

"I don't know whether to tall: much on residue, or the
poison from arsenical residue, or about the health from eating
apples in our state. There have boon no deaths at all from it."

LUT3 (62)

IASSEI1.Rki. A1.' i =3I .TZ h'JIEl EI.ETI R i_ II OBSr-OF"IW EACH DIR
Vp77' iT DUNG VOi KUPFEERKALKBRMHE ZUR 0BSTSCHDLINGSBEKAMPFUWG.

achrichtonbl. Deutsch. Pflanzonschutzdionst 9: 1-3. 1923.
Rev. Appl. Mjycol. 8: 386.

In 1927, 26 sheep, and in 1928, 274 sheep, 6 cows, and a
calf wore stricken with copper poisoning after grazing in orchards
wL.oerc copper sulfate had previously been used for pest control.

McCLUIC, P. J., and MITCheLL, H. H. (63)
TIM EFFECT OF FLL'O:RIE Ni TiE CALCIUM iLETA30LIS; OF ALBIi;0 BATS
AiTD 2'LE C0 LPOSITIO1 OF ThIiE BOES. Jour. Biol. Chcm. 90: 297-320.
1931.

Fluorine, especially when consumed in the form of the soluble
sodium salt, nay caxuso the deposition of L apparently abnormal
constituent in the bocnes, or an abnormal deposition of a non-calcium
constituent, possibly a fluoride of a mineral other than calcium,
as evidenced by an ir.crca(se in the percentage of ash in the bones above
the normal. There is also an interference with the deposition of
calcium in the bones brou-ult about by feeding fluorine.







- 19 -


McCUTCHOi:, A. (64)

I.SiIC; VITH SPSXALJ ZSR:?1TC3 TO ITS USE IN HORTICULTURE
A2J) AC-RICULTURE. Ph.-rnm. Jour. 116: 109-112; Chlcn & Dziruggist
104: 161. 1926.

The danger involved in eating -rsenically trot-ted fruits is
zi.ent i one d.

MciLTDOO, i. E., and Il2U'TH, G. S. (65)

=F72CTS OL: H:i-E.YBZ2S OF SPRAYING FRUIT THEES WITH AERSTICALS.
SU. S. Iept. Agr. Bull. 1364. 32 pp. 1926.

The nininun fatal dosage of arsenic (As203) for a bee
is about 0.0004 or 0.0005 mg. Bees poisoned when working in
sprayed orchards obtained most of the arsenic froi the pollen.

:,i;M.TT Y, p. (6()

lU3aR DI G2FAHIZI DZR AW-,D iUTG LRS-iTHAIJTIG-R .:;ITTL CGZiT
SCHID Ii'T. Ztschr. Decsirfekt. Gesuindhts-. 23: 245-268. 1931.

The danger, fr... the standpoint of health, of the use of
ar'sc.iAcal agents for pest control in orchards, vegetable gardens,
vineyards, etc., is e- phasized. A lengthy bibliography is appended.

MARCOVITCH, S. (67)

STJDIDS OF TOXICITY OF FLuO?.IND C0i.POUNDS. Tenn. Agr. 2xpt.
Sta. Bull. 139. 48 pp., illus. 1928.

The minimin lethal doees by nouth for man, based on
the values found f)-r na-rials, are: sodiur2 fluoride 30 g.,
sodium fluosilicate 7.2 g., potassium arsenite 0.84 g.

----- (68)

TI3 RESIDUE PRZOBLl AD FLUORRIi: COLiPOUNDS. Jour. Econ. Ent.
25: 141-142. 1932.

Of prime concern fro:-, the standpoint of public health
is the possible chronic rather than acute action of fluorine on
the system, as c2-pared with arsenic. Data are quoted which
show that both fluorine compounds and arsonicals have high acute
toxic values. As to chronic toxicity, the fluorine compounds
are at least 100,000 times safer than lead arsenate and possess
a marginal safety factor over the average s-"ray residue content
of 75.





20-

lSAlqir, A. L. (69)

COS:Ir. 7::S IHEN SPIAY1.G. rTsh. State Coll. Ent. Ext. Circ.
13. 2pp. [Liim. n. d.] BetterFr-.it 13 (9): 36. 1919.

Fruit trees in blossom should not be sprayed, and ex-
cessive spray that drips on alfalfa or vetch beneath should
not be a-polied. These measures are recommended to safeguard
the bees.

1iETZLT, C.-F. (70)

L'Ai:LTE DE PLOLiB ET VITICULTURE. Ann. Falsif. 9: 298-301.
1916.

The wines and "piquettes" do not contain poisonous
uctals (lead, arsenic, copper) when they are carefully freed
from the lees, but the latter contain a notable proportion of
leadC, and consumption of the above products before deposition
of the leeocs prcsonts a certain danger. It seems, therefore,
that an intensive arsenical tr&at:nent prolonged after the
fornr.,tion of the fruits does not intro( .icc poisonous metals
into products carefully prepared for consumption.

(71)

L S:-IIAE DE PL01'I3 TT" VITICULTUIE. Rev. Vitic. 46: 215-217.
1917.

Litcnsive a-rcnical treoatment of grape vinos, prolonged
after the formation of the berries, does not introduce toxic
nrtals (liad, arsenic or copper) into wines which are carefully
pre-arec7. The lees and marc retain them.

YiUTTEiIT, F., and TOUPLAI1T, F. (72)

LIAPSIjIAZ :E PL0..3 Ei VITICU"' ..u_ Ann. Falsif. 5: 9-16. 1912.

S-h grapes, mars, wines, "piquettes" and lees from vines
treated with lead arsenate do not differ in arsenic content
frou the products obtained front untreated vines. The wines and
"piquettes" (o not contain load. The lees in certain cases contain
a notable proportion of lead, and consumption of the wine or the
"piquette" before deposition of the lees would present a certain
an.'jr. The grapes may sorotinos retain sufficient lead to make
their consumption dangerous.

SYElS, ., .z TrE'-E, B., GUSTAFSON, P., rd KIl'SBUTRG, J. (75)

SIG.IFIAlTCE A:TD DA^-Ri OF SPRAY iESID,.E. Indus, and Engin.
C:-, r,. 25: 624-628. 1933.

Uctals play a part in the production of certain well-
defined clinical sn1ptoms, such as the development of bald
spots. i-.blcs -arc presented indicati:g that there is a seasonal





- 21 -


and gcog--'.-ic variation in the arsenic and. !cd cortntt
of fr.ito, vc--..l -i'les, ard canned ood.s. It s parent that
the nresert merhodr of wsn'ng and removing spray residues are
inefficient and inexact. This is particularly true in the
care of lead. 1he present srray residue situation constitr-tes
a men!-.ce to th- gne:eal wel-be>.l of the Tnubli, and the time
must comoe :'.en every L..vlru :: E ate will be vi!iling to tcu-e
a part in the regula-ory procedure.

--, VA DYCK, a Z (74)
:- AS :)' 'f iFI -
A?.s-.1:C IS A P :.LE: II: PF7^::? MAY PULIS Zi-TH IAAG^:^:T.
Led. Times 57: 134-142. ]2P

The occurrence of arsenic on fruit, duc to treatment
,''itnh insecticidres, in a&moun^s up to i/10 ,Train of arsenic trioxide
per pound, is _--so-rt .. a ut.iors contend that arsenic in even
smaller amounts than the I-eal tolerance is a LEnace to public
health. 7 t;, vegetables, ar5d f-ood 5''-ald >e free from metallic
co-ntamiuatiorns, t. he rse of-. inzccticides containing coper, l1o2,
or arsnc-ic should be abolished.

iF LS,:), . imUD-.Ar: A. :i. arn r.I :-I ", 0. (75)

77IU,1 AS A- 1'SE",IC1rS. Science 7-': 1i4. 1933.

Seloniumn in the soil is soimnilated souo plants,
rondoring them to-ic. Ordinarily, innocuous s- ray residues
co-.taini-',_ selenium might also bo absorbud .,y the plants and
converted into highly toric co'r t ons.

NfVTOi:, J. K. (76)

U-_ AALFIA L'EVIL I COLCTIO. Colo. Agr. Expt. Sta. ull.
"99. 19 pp. illus. 1933.

Sprmying the tips of alfalfa plants with an arsenicl,
such as load arsonate, calcium arsenate or zinc arsonite, is
recommended for the control of th2 alfalfa weevil, mpera
posticus Gyll. Properly sprayed hay (o. g., 2 lbs. of calcium
arsenate or 2.5 Ibs. of 7ine arsenite per acre) doe-s not contain
sufficient arsenic to i-:e it unsafe for stock food.

O'KAE, U. C., B.ALL, D. D. VIS, J.J., ... (77)
and SSI, 0.

SUPPLE ;'T TO PKOH SS ICF*RT O COI:i::-' 0 T TO TT STUAA-
:. v T- -,C -p.O '-
AF.STICAL rFIZU LS 0I FRUITS AS IH -77" SL OF SPRAY PF3PAX1S.
Jour. Econ. Ent. 20: 31-33. 1927.

It is raj.-me.ded that the U. S. "epartment of Agriculture
call in conference representatives of the Araerican 3 medical
Association, a physiolog:ical laboratory such as that of Chiciro




- 22 -


4Tnive:-sity, interested State e::pe.-imont stations, aid o-hars,
together rith experts in thu Dopartmt.nt, to plan a joint irnvec-
tigation that will disclose the basic facts with reference to
tolerrnco and that the Department of Agriculture and the State
exeriment stations gdve special attention to no'- agents for
control of injurio's insects and to control measure o other
than application of spra.ys.

..----, HADLEY, C. E., Jr., and OSGCOD, W. A. (78)

A-iC .nCAL RESIDUES A.LTK1 SPPAWIXG. F. H. Agr. E:-pt. Sta.
Bull. 19S. 62 pp. I3].7.

"This I'1llotin gite3 the results of cxpcrirents be Pn
in 112 and concluded in 1L.16, i.ateaded to provide further data
as to the amounts of ar-c-icai rusidre- remaining on fruits and
vegetables, after sprayirg with arsenate of lcad, the toxic prop-
erties of ars-nato of load, and tLo possibility of serious poison-
ing of livo stockl pasturcd on fora:;, containing residues of arsen-
ate of lead."

'Th> amounts cf arsn'.ic faltering to auy.les, strrwbcrries,
cur:nrints, blackberries, caobbgcs, and lettuce after spraying with
lead arsenate (3 lbs. of ppsto to 50 gals, of water) were deter-
mined experimentally. The maximum -mo'-.int that '.vould adhere to
apples directly sprayed was 4 m-. of arseniz trioxi.de per fruit.
The other fruits and vegetables were sprayed v'nd p.-'t of cach
picked before and. the rest after rainfall had occurred. The
ar'ounts of arsenic trioxide .7r3 in the following r--^os; strawberries
8.6 to 34.2 mb. per qt.; currant, 6.8 to 10.? m-. per qt.; black-
berries 3.8 to 11.2 ".- per qt.; cabbage 43.5 to 51.4 ag. per head
(including outer leaves); lettuce 1.6 to 10.6 ro. per head (includ-
ing outer leaves). The amount on alpries ordinarily sprayed
would probably not exceed 0.5 rmg. per fruit.

The solubility of lead arsenate in human gastric juice
was determined by A. J. Carlson and A. Woelfel. About 5 percent
of the arsenates of lead dissolve in human gastric juice when mxyed
in the proportion of 0.5 grain lead arsenate to 25 cc. of the juice.
Apple pulp increases the solubility but milk practically prevents
solution. Feeding experi.nts were also carried out on guinea pigs.

Fr-m the results of all this work the authors conclude "that
under ordinary conditions no app-les will reach the consumer carry-
ing such amounts of lead arsenate per fruit that a healthy human
adult can eat enough at one tine to cause fatal poisoning. Straw-
berries that are fully forrmd should not be directly sprayed with
lead arsenate, unless they are to be scrubbed before using. Black-
berries should not be dicir cctly sprayed after the berries are formed.
Currants, if so rpr%,-cd, should be washed. With cabbage and lettuce
reoc.y for market arsenate of lead should not be applied except
sparingly, and in that event the outer leaves should be removed
and the heads should be washed. The case is not clear as to





- 23 -


pocsi)le injurious effects front long-continued daily consumption
of frd ts carr'.ng relatively mia] 1 'es dues, but it is believe*
that the rse of aorles from trees sp, ayda with lead arsenate, at
the rate of 3 Ibs. of the poste to 50 gallons of water, offers very
slight danger, if any, this danger "oe^ng ne-lifib'e in the case of
viter fruit I rs2,ted two months or more pricr to harvest. Early
frjit Fo y3 Jus- before harvest should be wiped."

3xperimerts a-o *-,a to indicate that healthy calves may be
pastjred for a period cM grass ca2-rying considerable spray when
the strength of soliticn u3ee is 3 lbr-. lea:. arsenate paste to
50 :als. of water. At a corcentratior. of 6 lb.;. to 50 gals. con-
tijiued fdedirg iray rertult irn diinite -i- 7erieus syiiptoms of
r0ois5in^, while at 10 173s. to 50 gals. sericas or fatal poisoning
is likely to occur. Approxlra>ely the same results wcre obtained
with sheep, althoLge they wer- rouewnzvt rore r'sistant. There is
very little danger of p:iA;nIn, to cnhicl or hens eating grass on
which lead arsenate spia- h!.s lioped. Chickri.s are apparently
not especially susccotibec to Gad. arsenate poisonJng.

PAIGE, J. B. (79)

CACTTI POIS:.I::'G CR: LRJ-A: OF LEAD. Mass. A;r. Expt. Sta.
Ann. Rot. 21: 133-199. l9.

The anou;t 'f Lay obtai-ed front under a modiumn sized
tree -':.s found to be 50 Ibs. A3 lo: *..:- for a drip of 1 gal. in
10 of a spray -Iixturo of 10 lbs. of load arsenl-te in 100 gals. of
water, each 10 lbs. of hay would carry 9.06 gru.rs of le:d.
arsenate paste or abou-t half that amount of dry arsenate. The
results of eCp:eriments c.rndu't d by the author cn the toxicity
of lead arsenate to cattle indicate that a 10 pound feeding of
such hay would hardly produce serious effects but continuous
feeding of it for several da:%s in succession certainly would
do so and animals oajld probably. eat sufficient to cause fatal
poisFoil ng.

PEAKCCER], T. (80)

ARZEY IC 01. APPLES. 3u11. C,-.m-nber iort. [Loidoifa] 3 (1): 11-13.
1926. [Abstract in Beo. Apple. Snt. (A) 14: 218. 1926.]

Recent e:xanLnation has showm that while Eilish apples
bear only negligible traces of arsenic on- their skins, imported
fr'.it bears ar3e..ic slightly in excess of 0.01 grain per pound. It
has re-certly been Fug-ested, and unfortimnate1y definitely stated
in the press, that arsenic is present in the flesh of the apple
and that neither nvwhl'g nor nrt(ling will completely eliminate
it. It is true that arsenic in very rmin'.to doses miy be taken
uo by the roots of the fruit tree in the nutrient solution, but
there should be no (an&er whatever of such contamination ever
being efficientlyy co.centr"ted/to constitute a danger to health.
Factors ii-fluencing the adh-esivenoss of arsenicals to sprayed





Z4 -

r'uai? and. the amount of deposit r( mainring on the fruit are the
use of a spread.er or adhesive substance in. the spray, the
physical properties of the spray (fineness of subdivision), and
the extent of rainfall imnimedidteiy following spraying operations.
If a heavy shower occurs' shortly zftcr an application of lead
arseiate arid caseinate, much of the poison will be washed off, bxt
if there is no ra'.n for a .ay or two, the poison will have adhered
firmly "i-d subsequent w.:-.shng will have little effect. If an apple
cor'taninated with this Jenposit be washed with water, the deposit
is very difficult to remove, vigorous polishing being necessary to
make any impression. The question of eliminating this danger or
reducing it to negligible quar.tities is a serious one. One
measure to be considcrec. is.wipi.-g the frait before packing, but
this would prove rather co.,tly. Tho use of less po isonous in-
secticides has been investigated, but there are very fow materials
that are likely to forn a suitable substitute for arsenicals.
The possibility of attacking Carroc.psa pomonella at some other stage
than the la.rval requires inverti-ation. Close ins.cction and
analysis at the port of entry might be arranged by. the Ministries.
of Ariculture and Health ar-. the Tort r'ed cal authorities.

PORCMI T (81)
&
LES TEAITELIHTS CULTTTALTX ALLX S3LS D'A .iSETIC ET LIHYGIEi3
ALIIi.TAIEE. Hyg. Bur. *Ssnit. Fed. 48: 79-83. 1910. Sch-ioiz.
Uchnschr. Chem. u. PThsrm 48: 6c4-696. 1910.

Analyses for rrsenic on fruits treatci with arserical
insectides and on untreated fruits indicates that the rational use
of such insecticides at the prescribed time, not later than one
wIee'.: after blossoming, presents no J.anger to the consumer, Late
applications may cause serious accidents.

PORTER, B. A,', JUA:I-TANCE, A. L., DEAN, G. A. FLIITT, W. P., (82)
PARI-TT, p. J., and CHILDS, C.

R-'ORT OF COLDIiITTEE TO FOR1hTLATE PLAYS FOR INVESTIGATIONS OF
SE, CODLING MOTH FhO! BIOLOGIC AID C0i:TPOL STAiTDPOIi.TS. Jour.
'con. Ent. 21: 31-38. 1928.

The results of experiments looking to the avoidance of
excessive spray residue are reported. Dusted fruit carries
residues well under 0,01 grain per pound. Before any possible
substitute for arsenato of lead can cone into commercial use, it
will be necessary to deterri.io the nargin which may exist between
thec amount of residue the substitute loaves under various con-
ditions and the quantity of substitute which is likely to be
considered deleterious to hunan health,





S25 -


POTTS, -. C. C(33)

I-SI-i MiUST GO, SAYS GO'&0LKEiT. Bettor Fruit 22 (1). 724. 1927.

An editorial. 7i. G. Campbell is quoted as saying that
the question is not whether perfect solvent and removal devices
have been evolved but whether fiuit safe for consumnntion is turned
out. 3. Smith, United States -arsEting agent in Europe, is also
quoted, showing the grave d(cir;:er to the trade of American apple
exports because of s-pray residues on fruit exported.

PRICE, 7. A. (-84)

JS A'ITD THZIR -?LATIO 1O ARS:oICAL SPPAYS AT BLOSSCI.:I:- TILS.
Ind. Agr. Expt. Sta. Bull. 247. 15 pp. 1920.

The Gutzeit method of determination of arsenic appears
to be sensitive enough for -iost doses that kill bees, although
sobie very small fatal doses may escape detection. Less than
0.0000005 g. [0.5 :.icrogram] of arsenic trioxide is a fatal
dose for a bee. Bees work freely on sprayed trees in the open
even when there are unsprayed trees all about. For the sake of
the bee, fruit trees should rnot be sopr-ayed while in full bloom.
t
RES, H. L. (85)

LA1TC-R FBORi LEAD AR-.:AE POISOYIiTC-. Wash. A-r. Expt. Sta. ,io.
Bull. 2 (7): 11. 1914.

The author qtlotes evidence froi., several sources to show
that fears of eating sprayed vegetables and fruits are groundless.

B3EVES, G. i. (86c)

TE3 A2SZYICAL POISOi-i'.- OF LIVE-STOCCK. Jour. econ. Znt.
18 (1): 83-89. 19?5.

Reco-mmendations for the spraying of lucerne to control
the alfalfa weevil, Hypera (Phytononus) :.71Iina F., have been
gSuideod largely by the work: of Dr. E. C. Gardiner on the
arsenical poisoning; of do-Iestic animals. It deals with the
tolerance of farm animals for arsenic and describes the symptons
of arsenical poisoning and the lesions produced br it. It was
proved that horses and cattle can take from 20 to 30 grains of
arsenic daily, for an indefinite period, v',ithout any external
evidence of injury or any alteration discernible upon post-norton
examination. S',ec-. are noro easily poisoned, requiring only 4 to
8 grai- s daily. The fatal dose for horses and cows is 300 grains.
The damgorous dose is shown to be far greater than the ,amount that
is contained in a food of sorr-ycd hay.




- 26 -


ROARK, f. C. (87)

I:SCTICIEES SPTDIED TO Ii:CPASB El-FECTI-VE ISS AlD DETE .
C--AFER ;ZTIODS OF :"ArjIACTUM. U. S. Daily, Anril 25, 1928.

"Lately health officials have objected to the ao ,rontly
excessive quantities of arsenic and. lead upon "pplcs and other
fruits and vegetables wnich have been sprayed vith arsenical
inscticides. Arsenic and lead are recognized as deleterious
substances, and the -ohysician properly objects to more than
traces of these, particularly 1oad, i-- foodrtu.fs."

(0-8)

C:r. :IC-LLU COiBATIUG 1i SZCT PESTS OF FOODSTUFFS. Indus. and
.. Cher. 24: 646-648. .:..

On account of the volatility: of free nicotine and the
reacy solrbilit- of both nicotr.ne and nicotine sulphate in water,
fruits and v -etables rarely have on thon detectable quantities of
nicotinec. Casrs are on record, however, of persons suffering
ironi nicotine osonin cd'.;.o to eating lettuce fro:.i a greenhouse
whore nicotine had bcoi r-ccc'tly soraycd. The use of arsenical
co-no'unCLS- on fr-dts and. vegetables caLISos muc.'i concern because of
the arsenical rosilxc left. Apple grov:ors have bocn compelled
to .ash. t-he fruit ir: dilute acid or alkaline solutions. Efforts
to fnd a substitute for letad arsenate for codling moth control
have boon under vay for nxniy years. Certain fluorine compounds
have shown the nest oronisc of any materials of inorganic
ori-in. Thc question of tolerance for fluorine remains to
bo dotcrmined.

ROBI-TSOV., D. H. (89)

A2ES2rIC l'T APPLE.S. Fcitiliscr, Foeeding-STuffs and Far-
Suvplies Jour. 11: 600-601. 19266

T'h.-re is no danger of arsenic in English-"rown .pples,
a, one spray of lead arscnatc. is s: fficiont to control the
codling noth in that country. In Anerica repeated spraying
-s ;.ecossary. Samples of foreign apples, mostly Ancrica-x.,
coioai -icd as much as 1/30 to 1/10 rain of arscr-eic (As203)
per pound. The risk: of death or serious poisoning fror arsonic
in ..:- apples is c~ 7icoerably less than that incurred in
crossin: a busy city street.

ROTHPLETZ, F. J. (90)

SODIUM FLUORIDE A SAFE IiTSECTICIDE THE3 PROPERLY USED. Prog.
FYrni-no (?) 35.S 1197. 1920.








27 -

ROUGER, :, (1)

AU SUJET DES ITS ECTICIDES ET AkTICYPTTO:-JrHIQUES JT DES DA:,GERS
0qU'ILS PiSSNI!,TT. Progr. Agr. et Vitic. 92: 422-425. 1930.

Sheep fed for a period of a month orn green clover soaked
in bordeaux mixture showed no signs of ill effects, and chemical
examination of the flesh and other tissues of one of the sheep
revealed no copper.

RJEDIGEE, E. (92)

SCDLIITGSB K:.FD-UTG -IT AR iT. Ent. Rdisch. 48: 11-14. 1931.

The dangers in using arsenical dusts for pest control
are erli? sized.

SCHULZ, 7 H., and THO1iOi', IT. F. (23)

SOiE EFBCTS OF SOLILn. A.^'.ITr 7 ,TI^ USz-D TO TI!LL i CTiUC.iT
BA^E.--xRY. U. S. Dept, A-r. B.l, 1316. 18 pp. 1925.

In using arsenic in ]-rilalg vieeiP, its extreme toxicity
to animals must be considered. Cattle .re attracted by the
taste of arsenic. Repellents, such us aloes, have been used
with success.

SCHULZ, J. A., and LA.4, A.# (94)

TH EF .FCT OF FLUOEI AS SCDIL. LUORIE Of T11 GRCB.TE AND
REPRO:UCTIOIT 0O ALBIi3O PR:S. Science In. s.] 61: 93-94. 1925.

iHo ill effects on Xrowth and well-being are observed until
0.10 percent of sodium fluoride is fed in the ration of the rats.
A very marked toxic effect is observed wher- 0.15 to 0.25 percent
ic fed. Apparently an unfavorable effect on reproduction te&'ns
at a level of about 0.025 percent sodium fluoride. The fluorine
caused abnormal growth of the u-,er incisors of the rats.

SEIITH, .. C., and LRI'.T0, R. Li. (95)

COl^AP?_I\ TOXICITY OF FLUCRUi CO0cUi:DS. Indus. and Engin.
Chem. 26: 791-797. 1934.

The toxicity to yo'i-g albino rats of sodiumu, potassium,
am.oniun, and calcium fluorides, sodi-um, potassium, and barium
fluosilicates, and natural cryolite (sodium aluminu-n fluoride)
was studied. Cryolite and calcium fluoride, the least soluble
of these compounds, vwerc many tines less toxic than the other,
more soluble compounds frou the stinripol-nt of their effect upon growth
rate and food utilization and of the amount necessary to cause
death. Fluorine interfered with the normal process of reproduction
only at those levels of foeding which resulted in stunting in grcoith






- 28 -


of the female. Concentrations fr below these nocc--sary to ir.t*-::f.'e
with Cro-th or general health caused damage to the incisor teeth.
I-ULh Lore of the cryolite and calcium fluorid, than of the other com-
pounds was required to cause corrosion rnd pittiii of the enamel,
but all of the compounds of f.luo.-Ine studied left a mark characterized
by the rppc',rance of fine, lighter pigmenrt lires on the incisor teeth
when incorporated in tha diet (for 6 weeks) at a 0.0014 percent
(fluorine) level (14 p.p.m.) or fed s e.pratel1' in daily doses of
O.Z mg. fluorine to ycung rats or fed at the level of 1 m4. j"er
kg. of body weight.

s6 YTH, H. F., and SIMYTH, H. F., JR. (96)

ELATIVE TOXICITY OF SO '1JiUOFI1J? ATT _RSE.IAL IITSEQTIC:_ DE.
Indus. and Engin. Chem. 24: 229-232. 29"2.

The relative toxicity of fluorine and ar'ernical insecticides
was determined by feeding to white rats variol's accurately m-c.as'u ed
amounts of cryolite, barium fivosilicate, rnd lead 11scnate mixed
with their food for 16 weeks. The results, including behavior,
appetite, fec-undity, growth, tooth dcvelopoent, and organ path-
ology, a-rce in indicating th'- arenic'Q coiTr-ound to be sever:.l
times as toxic as the fluorine conrTpouni-s.

SC'LLIMKT, T., : HETTLER, 0. H., r. nd ZEZ3L, 1. C. (97)

STUDIES OF. CI3ONIC I1TOX:CATIONS ON ALBINO PATS IV. FLORID, CHLOFID
AND lC4LCIUM (TNCLUDIi-C SODIUM FLUOLID, SODIL:.: CHLORID, "PHOSPHATE
ROCK", CALCILUI PHOSPHATE (P7ECIPITATED) A:,! CALCIUM CAROIA:IE
(FtEZIPIPTATED). Jour. Pharmacol. and Expt. Ther. 17: 197-225. 1921.

Sodium fluoride eaten "'ith food during long periods in daily
doses of 15 to 150 mg. per kg. of body weight results in progressive
in.pairment of growth and food consumption. The damage is prc.ortional
to the dose. It tends to outlast the administration of the drag, so
that the gro'vth of animals that have been poisoned with fluoride remains
permanently below that of unpoisonrd animals. 1lo deleterious.effects
on growth or food consumption occurred in 9 weeks with daily- des7- o.-
sodium fluoride of 8 mg. per kg. of bdvy wr7ight er less.

STEIHTI, L. F.; AZKEiA;lA, A. J., and LADoILTCI, DW. W (98)Y

THE VALUE OF SUPPLEI:E1NTARY iiSASUFES I" TIHE CODLING MOTH CONTROL
PROGCI'M. Ind. Hort. Soc. Trais. 1934: 34-40. 1935.

The point has been reached in the apniication of lead arsenate
for codling moth contr-ol where the poison nredcd to control the pest
is not only dangerous to humans if it cannot be removed at harvest
time, but is injurious to the tree itself.

ToP. E. (99)


SPRAY POISONING. Wash. Farmer 42 (8): 13. 1919.







- 29 -


TAL ERT, T. J., and TAYLOE, 7T. L. (100)

1-:- LIGHT ON T1- SPRAY RSIDL-E PROBLEM. Amer. Fruit Grou.err
51 (2): 5-7, illus. 1931. [Also in Amor. Soc. Hort. Sci. Proc. 1930:
538-542. 1931.]

From the results of their tests on rats, the authors conclude
that a man would have to consume at one time 100 pounds of fruit
containing 0.02 grain of arsenious oxide per pound to cause mny
harmful effects.

---- Ai TAYLOE, 1. L. (101)

S0O; -SiTS FROi: FEEDING SPFjAY CHEmICLLS TO 'JlII-70 FPJTS. iHo. Agr.
Expt. Sta. Reos. Bull. 1C3. 19 pp., illus. 1933.

"Arsenic as arscnLc trioxide or in combination with the lead
in the form of connercial lead arsenate, or with calcium arsenate
and lead acetate, j-peiars to affect albino rats as follows:

"Arsenic salts in quantities ranging from the equivalent of
four times to two hundred times the official world tolerance may
proiiote activity and ,ro'-th in the original stock for the first
twenty-three to twent,--five weeks.

"Dosage of insecticides continued for periods of more than
fifteen weeks decrease the ability to raise yc-ong in the first
generation.

"Arsenic did not appear to retard growth unless fed in quantities
larger than the equivalent of 0.04 grain arsenic trioxide per pound of
fruit.

"Lead as lead acetate and arsenic in its various forms as an
insecticide appear to have injurious effects on albino rats only after
prolo ,-.d feeding.

"Arsenic or 1,ad, or both, ,vh.n fed in quantities l:.rger than
the equivalent to 0,04 grain for about 175 days, seemed to have an in-
jurious effect on the offspring by decreasing the weight and the ability
of the females to produce and rear young.

"h'non spray chemicals are fed daily qver lon, periods in quanti-
ties equivalent to more than four times the world tolerance, they have
very marked injurious effects on albino rats, and '-hen the feeding is
c:;:t.nded for four hundred days or more, the mortality rate increased and
aJnCaounted to as much as 35.4 percent.

"Contrary to general opinion, the spray insecticides do not have
as acute toxic effects on albino rats as is generally supposed, even when
used in amounts of two hundred times the official world tolerance.

LIBRARY
STATE PLANT BOARD








30-

"Our experience indicates that the arsenicals in fruit sprays
in fact, acute stimulating effects' and injurious' effects are brought
.only when feeding is regular and prolonged, -as shown In "the feeding
periods ranging from 378 to 497 days.

"If it may be assumed that the spray chemicals have an effect
upon man similar to that which they -have upon albino rats, it is the
opinion of the authors that there is little likelihood of a human
consuming as spray residue on apples, sprayed and handled in the
usual manner, enough arsenic either at one time or over an extended
period to be injurious. In view of the varying effects of lead
poisoning given in the literature, the tests made in this experiment
do iot appear adequate to justify the drawing of conclusions as to
the risk of lead poisoning from the consumption of sprayed* apples."
(Authors' abstract.)


have
on


T>:-'.I AS, E. F., and SHEALY, A. L. (102

LEAD AISEUATE POISO'UIG IN CHICKEUS. Jour. Agr. Research 45: 317-319.
1932.


)


During the spring of 1929, numerous complaints were received
from poultry owners in areas ofFlorida where lead arsenate spray *as
being used in combating the Mediterranean fruit fly. The spra-/
formula used was: lead arsenate, 8 lbs.; brown su!Tar, 50 lbs.; syrup,
10 gals.; and water to make 200 gals. Approximately 7 gals, of this
spray was used on an acre of citrus. The results of the experiments
here reported indicate that 168 hens could consume this amount con-
tinually for 60 days and suffer no ill effects. It would seem, there-
fore, that it is impossible for chickens to consume enough solution
or sprayed foliage in a sprayed grove to suffer from the effects of
lead arsenate poisoning.


TROOP, J.


(103)


BLOSS01 SPRAYI TG AND BEE POISOWIING. Jour. Econ. Ent. 11: 433. 1918.

Experiments under way at the time of writing seem to indicate
that bees may be killed by a poison spray at blossom time.


VEiXATA_-OYAN4, S. V.


(104)


ARE SPRAYED GRAPES POISONOUS? Jour. Mysore Agr. and Expt. Union
14 (1): 22-24. [n.d.]

An adult can absorb daily for a period of weeks without ill
effects from 0.2 to 0.5 g. of copper sulphate. Sprayed grapes on
analysis hLve rarely been found to contain more than 5 mg. of copper
per kg., the aver -ge being 2 1/2 to 3 mg. per kg. On this basis an
adult may eat from 300 to 500 lbs. of sprayed grapes per day with-
out fear of ill effects from copper. Allowing for the insolubility








- 31 -


of the copper in bordeaux mixture, this quantity is easily raised
to 1,200 to 2,500 lbs. per day. Similarly, a man who drinks
sprayed tea prepared in the ordinary manner does not exceed the
limit of safety if he keeps himself within 10,000 large cups a day.

WAKELAND, C. (lOS105)

SEASONAL VARIATION AS IT AFFECTS -THE ACTIVITY AIMD CONTROL OF
THE ALFALFA W"EVIL IN IDAHO.* Idaho Agr. Expt. Sta. Bull. 138.
11 pp. 1925.

The preponderance of evidence is that there is no danger
to livestock from eating hay properly sprayed with arsenicals.
Two cases are cited which seem to indicate that under some
conditions the presence of arsenic aggravates digestive or
excretory disorders.

'TEBSTER, R, L., and CREWS, A-. (106)

SPRAY POISON IN THE YAKIMA VALLEY. Jour. Econ. Ent. 27: 614-617. 1934.

Poisoning of bees by lead arsena.te sprayed on fruit trees
and potatoes is discussed.

WILCOX, E. V. (107)

APPLES A!TD ARSENIC. Country Gent. 91 (5): 21, 85, 86. 1926.

Care in spraying with arsenicrls is urged to prevent
the occurrence of excessive amounts of ;rsnicnl residue on
apples.

W7ILLSCN, R. B. (108)

A POSSIBLE EFFECT CN FRU:T GROWING BY EXTENSIVE USE OF ARSENICAL
DUSTS IN ORCHARD. N. Y. State Hort. Soc. Proc. 71st. Ann.
Meeting, pp. 38-42. 1926.

Poisoning of bees by arsenical dusts applied to orchards
when flowers frequented by the bees were in bloom is reported.

WILSON, H. F. (109)

WILL FLUORINE COMPOUNDS BE ACCEPTED AS INSECTICIDES? Jour.
Econ. Ent. 27: 291. 1934.

Experimental data secured at the Ohio &nd Wisconsin
Agricultural Experiment Stations show that fluorine is an
extremely toxic and dangerous poison when fed to animals. The
teeth and bones are so affected that when complete data are
published a psychological reaction is certain to arise against
the use of any fruits or vegetables sprayed with fluorine
compounds.







- 32 -


UTOMXCK, R. P. (110)

SPRAY RESIDUE.. Blue Anchor 6 (5): 18,' 36-37. 1929.

"While .the people of some nations eat arsenic and find
its use helpful, others are afraid of the very minute quantity
th-.t may remain on matured fruit as a result of its use in
insecticide sprays; and the removal of spray residue has
gradually become one of the important problems of the pear and
apple growers." The history of the spray residue situation in
the United States is outlined.

WOODBURY, 0. G. (Ill)

REPORT OF TIE DIRECTOR. Ind. Agr. Expt. Sta. Ann. Rpt. 32. 100 pp.
1919.

Two bearing apple trees were screened in and a colony of
bees placed in each. The trees were treated with arsenicals
while in bloom, one with a liquid and one with a dust. Dead
bees were gathered arid counted at intervals and the results
showed a mortality of about 70 percent for the sprayed tree and
46 percent for the dusted tree. Other observations showed that
bees do work sprayed trees when they are at liberty and there are
unsprayed trees adjoining. Nearly all the dead bees gave a strong
Gutzeit test for arsenic.

WOODORTH, C. W.. (112)
[REPORT OF DEPARTMENT OF] ENTOMOLOGY. Calif. Agr. Expt. Sta.
Rpt. July 1, 1913, to June 30, 1914, pp. 109-118. 1914.

A hive of bees was placed in the center of a 40-acre apple
orchard just before spraying with an unusually heavy dose of
arsenicals as the trees '.ere just coming into full bloom. Honey
stored at this time did not contain arsenic, although on analysis
of some dead bees nearly a toxic dose was recovered. Therefore
even under such severe conditions there is no appreciable danger
to man from poisoned honey.

II. LSGAL ASPECTS OF THE SPRAY RESIDUE PROBLEM

ANONYMOUS (113)

ARRETE DU 30 DECEMBRE 1916 MODIFIANT ARTICLE 2 DE
L'ARRETE DU 15 SEPTEMBRE 1916 FIXANT LES CONDITIONS
DIEMPLOI DES COMPOSES ARSENICAUX pN AGRICULTURE. Jour.
Agr. Pratique 81 [n. s.]: 32. 1917.

Treatments with arsenical powders or washes are
forbidden in vineyards, orchards, and other plantations where
intercalary cultivation of market and kitchen gardens is
carried on. Authorized periods for arsenical treatments
are: 1. Vines, from the end of the harvest to the end of





- 33 -


blossomings. 2. Apple, pear, and plum trees dur ,he period
from the end of harvesting until 15 days after blossoming;
at the time of full blossoming, treatments will be suspended.
3. Olive trees, June 1 to October 1. 4. Beets until a
month after transplanting; 5. Osiers at any time; 6. Nursery
trees and shrubs 'at any time, provided that they carry no fruit
destined for consumption.

(114)

PROROGATION DE L'IEMPLOI DES SELS ARSENICAUX DANS LA VICG:E.
(DECISION M'ITISTERIELLE DU 27 AVRIL 1921.) Rev. Agr. Afr.
Nord. 19 (98): 461-462. 1921.

(115)

SPRAY RESIDUE MUST 1E REMOVED, SAYS COURT. Calif. Fruit
News 74 (2003); 3. 1926.

A verdict in favor of the Government was returned
by a jury in ChiQago in a test suit involving 2,294
boxes of apples of the Sun Crest Orchard Company, Rogue River
Valley, Oregon. The company has the choice of destroying the
shipment or cleansing it of the spray used.

(116)

OVERCOMIIIG SPRAY RESIDUE TROUBLES. Calif. Cult. 69 (7): 151.
1927.

The State department of agriculture is making every effort
to assist California growers to clean their fruit and see that
no shipments leave the State in violation of regulations.

(117)

SPRAY RESIDUE ON FRUIT. Rural New Yorker 88 (5066): 963. 1929.

All fruit Placed on the market in New Jersey should
meet the domestic tolerance of 0.017 grain arsenic trioxide
per pound.

(118)

SPRAY RESIDUE REGULATIONS. Calif. Fruit News 79 (2133): 9.
1929.

The regulations issued by the California State Depart-
ment of Agriculture for carrying out the provisions of the
spray residue act of 1929 are given.



SPRAY RESIDUE. Calif. Dept. Agr. Mo. Bull. 18: 363-364. 1929.


Two field laboratories will be established this





-34-


season for analyzing export shipments. The domestic.
tolerance for the 1929 season is 0.017? grain per pound.

(120)

SPBAY AEStDUE AMND LAW IFORCEMNT. Calif. Dept. Agr. Mo.
Bull. 18: 464. 1929.

Each year the spray residue inspectors find less
difficulty in enforcing the spray residue law. It is
aprrarent that the cleaning of fruit has become a regular
practice.

(121)

LEAD RESIDUE LIMIT ON FRUIT IS REDUCED. Oil, Paint and
Drug Rptr..123 (17): 15, 29. 1933,

A limit of 0.014 grain of lead per pound of fruit
has ee.L set for the 1933 season. The arsenic tolerance of
0.01 grain of arsenic trioxide per pound is continued.
Growers are warned against fluorine compounds.

---- (122)

APPLES OF DISCORD. Business Week, No. 194: 14. May 24,
1933.

All apples and other foods must meet the limitation
of 0.014 grain of lead per pound to avoid seizure, effective
with the products slipped from the 1933 growing season.

ASSOCIATION OF FOOD OFFICIALS (123)

R0,RT OF CC.:,.;TTl= ON SPRAY RESIDUES, ASSOC:JATO. FOOD AND
r, F' F.CjA!.S Neb. State Hort. Soc. Ann. Rpt. 62: 41-44.
1931. Neb. State Agr. Bd. Ann. Rpt. 1931: 479-483.

The reduction of the arsenic tolerance to the world
tolerance of 0.01 grain [arsenic trioixde] per poundifor
the 1931 crop of fruit is recommended.

CALIFCFPI IA D:FArTMi7,-, OF AGRICULTURE (124)

RITLES .AQD P.VruG.. OJS. FOR CARRYING OUT THE PROVISIONS OF
THi SPRAY RESIDUE ACT FOR 1929. Blue Anchor 6 (5): 19.
1929.


CAMPBELL, W. G. (125)

REPORT OF THE FOOD, DRUG, AND INSECTICIDE ADMINISTRATION.
16 pp. 1928.

Supervision of interstate traffic in fruits and
vegetables subject to contamination with spray residue






- 35 -


has continued.

(126)

REPORT OF THE FOOD, DRUG, AND INSECTICIDE ADMINISTRATION.
18 pp. 1929. :

Comparatively few lots of fruit from the Pacific
Northwest in 1928 contained spray residue that might be
harmful to the consumer. The washing equipment has proved
most effective.

(127)

REPORT OF THE CHIEF OF THE FOOD AID DRUG ADUIITISTRATION.
25 pp. 1930.

A systematic campaign to determine the character of
sprayed fruits and vegetables entering interstate commerce
and their status under the provisions of the law was in-
augurated in 1919. Succeeding seasons have seen increased
activity until at present the project has attained such
importance that during the shipping season much time
of the field force is devoted to this work.

(128)

REPORT OF THE CHIEF OF THE FOOD AND DRUG ADMINISTRATION.
30 pp. 1931.

It was seldom necessary during the past year to
resort to legal action against shippers of fruits and
vegetables containing spray residues, although 10 seizures
of fruits and 9 of celery were made.

(129)

REPORT OF THE CHIEF OF THE FOOD AID DRUG ADMINISTRATION.
18 pp. 1932.
Steps were taken to remove 40 consignments of
cabbage and 26 of celery, heavily contaminated with arsenic,
from the market by seizure. For a number of years fruit
growers have been washing their fruit so effectively that
*the chances of its carrying excessive spray residues are
small. Vegetable growers, however, have not fully realized
the need for employing similar methods where heavy rcisonous
sprays are required as a preventive of insect and disease attacks.

(130)
REPORT OF THE CHIEF OF THE FOOD AIND DRUG ADMINISTRATION, 1933.
19 pp. 1933.

Following the adoption by certain apple packers of
washing solvents other than hydrochloric acid, the development
by the Department of Agriculture of accurate methods of






- 36 -


analysis for minute quantities of lead led to the discovery of
commercial shipments of apples satisfactory as to arsenic but con-
taining high lead residues. On June 20, 1933, the Department
announced a tolerance of. 0.02 grain of lead per pound of fruit, No
tolerance is recognized'for lead on vegetables. A tentative
tolerance of 0.01 grain of fluorine per pound was also announced.
Rapid and accurate methods for fluorine determinations were devised
by the Administration chemists. During the period July 1, 1932, to
March 1, 1933, approximately 7 percent of the fruit and 6 percent of
the vegetables exnanined for arsenic were above the tolerance.

(131)

REPORT OF THE CHIEF Of THE FOOD AID DRUG ADMINISTRATION, 1934.
18 pp. 1934.

The lead tolerance has been reduced to 0.019 grain for the
season of 1934. It cannot be anticipated that spray reEidue activities
will slacken in the near future. Conditions, so far as interstate
traffic is concerned, are improving.

DRINKARD, A. W., Jr. (132)

THE AGRICULTURAL EXPERIMENT STATION. Report of the Director. Va.
Polytech. Inst. Bull., Rpt. of the President 1930-1931: 53-59. 1932.

The activities of the staff with regard to the removal of
spray residue from fruit are briefly outlined.

FORMENTI, C. (133)

UEBER DIE VERBREITUNG GIFTIGER METALLE IN NAHRUNGSMITTELN.
Z. Nahr. Genussm. 21: 265-271. 1911.

Arsenic may occur in wine when the grapevines have been treated
with arsenical insecticides such as lead. arsenate, alkali arsenites
and arsenates, copper arsenate, etc. For this reason, the French
Government on Oct. 23, 1908, forbade the use of such arsenates on
grapevines.

GEAGLEY, W. C. (134)

WHAT AN ANALYSIS OF THE SPRAY RESIDUE PROBLEM REVEALS.
Mich. State Hort. Soc. Ann. Rpt. 61: 61-65. 1932.

A discussion of the activities of the Michigan State Department
of Agriculture with regard to' the spray residue problem and of the
situation in Michigan.

GRINER, J. I. (135)

EXCESS SPRAY IS TABOO THIS YEAR. Better Fruit 20 (II): 8, 18.
1926.
Great Britain will accept no exported apples having more than
0.01 grain residue per pound. Spraying practices which will minimize
the amount are outlined.








- 37 -


H., G. H. (136)

SPRAY RESIDUE, Calif. Dept. Agr. Mo. Bull. 17: 435. 1928.

A letter from F. W. Pettey, senior entomologist of the Union
of South Africa, is quoted. He states that in that country all apples
and pears for export which have received one or more arsenical sprays
must be treated for removal of the residue by dipping the fruit for
1 or more minutes in 1/2 to 1 percent actual hydrochloric acid, followed
by draining and thorough rinsing in clean water. No fruit containing
more than 1/100 grain of arsenious oxide per pound was allowed to be
exported.

HANSEN, A. W. (137)

A DISCUSSIOIT OF THE ARSENICAL SPRAY RESIDUE PROBLEM.
Idaho State Hort. Assoc. Proc. 32: 71-76. 1927.

From a legal standpoint there is no room for argument against
the proposition th.t excess arsenical rFrry residue must be removed.
The economic demand for the removal of arsenical residue before the
fruit goes to the consumer i- even more potent. The solution of
this problem during the coming season lies in reducing spray
applications to the minimum consistent with protection of the fruit,
.nd, ifnecessary, adopting one of the methods of cleansing which will
be recommended as a result of experimental work under wmy.

HEITK, F., REC mNDORER, P., and BERAIT, F. (138)

UITTERSUCHUNGEI UBER DEI ARSETGEHALT VON TRAPBEN UND .,10ST
ALS FOLGE DER SGHADLIITGSEE.:AI,2FUNG. Wein u. Rebe 11 (1).
Reprint. 5 pp. 1929. [Abstract in Rev. Appl. Ent. (A)
17: 575. 1929.]

Investigations are reported on the amounts of arsenic traceable
on grapes and in must as a result of the use of insecticides. The
Austrian regulation forbidding (1) treatment with arsenicals after
August 10 in each-year and (2) the removal of grapes for wine making
until 5 weeks have elapsed since the last treatment is shown to be
justified.

HOWARD, L. 0. (139)

THE USE OF ARSENICALS IN FRE1ICH VINEYAP.DS. Jour. Econ. Ent.
21: 510. 1928.

The French Ministry of Agriculture issued an order on February
25, 1928, permitting the employment of arsenicals in vineyards
between the date of the yintage and the time when the grapes begin
to darken the next season.






- 38 -


JAMES, D. M. (140)

HOW THE STATE DEPARTMENT OF AGRICULTURE CHECKS UPoON ARSENICAL
RESIDUES. Penn. State Hort. Assoc. News 73: 109-111. 1932.' -

An explanation of the activities of the Pennsylvania State
Department of Agriculture with regard to spray residues on apples.

LEUZINGER, H. (141)
'DIE ARSENFRAGE IN DER SCEWEIZ. Verb. Deut. Ges. Angew. Ent.,
6. Mitgliederversaml,. Wieri28. Sept.--2. 0kt. 1926, pp. 44-48.
1927. CAbstract in Rev. Appl. Ent. (A) 16: 6. 1928.]

In Switzerland the free use of arsenical insecticides is
hampered by legislative restrictions, the legislation being largely
enacted by the various individual cantonal republics forming the
confederation. The text is given of the regulations dated March 31,
1926, governing the use of insecticides in the canton of.Valais, Pnd
also -he results of experiments by the author there, which show the
great value of lead arsenate againstt the vine moths, Olysia ambiguella
Hb. and Polychrosis botrana Schiff.

AAG, R. (142)

SOMMERSPRITZLNG DER OBSTBXUME ZUR BEKiX-IPFUNG VON SCHOEFR UND
OBSTMADE. Schweiz. Ztschr. Obst-u. Weinbau 34 (8): 152-156.
1925. [Abstract in Rev. Appl. Ent. (A) 13: 302-303. 1925.]

At present lead arsenate for spraying can be used in Switzerland
only experimentally and under special supervision. To make it better
known there these reports of results obtained in 1922 and 1924 are
published. A mixitre of 2 percent lead arsenate solution and 1 percent
bordeaux mixture was used in summer, and a great reduction of attack
by scab and Cyaia 1ouonella was attained at a cost that was only a
fraction of the crop value saved.

MEEK. J.. H. (143)

INSPECTION PROBLEMS. Va. Fruit 21 (1): 30-36. 1933.

Since the inspectors of the [Virginia] Division of Markets
are in the field and in contact with the apple industry, they have
been designated by the Director of the Dairy and Food Division to
represent him in dealing with the spray residue problem.

MELINE, J. (144)

INSTRUCTION ET ARRETE DU 15 SEPTEiIBRE 1916 RELATIFS LA, VENTE ET
A L'EZPLOI EN AGRICULTURE DES COMPOStS ARSENICOAUX.
Jour. Soc. Natl. Hortie. France 17: 146-149. 1916.





- 39 -


Treatments with arsenical compounds are forbidden in vine-
yards, o-cht4rds, and other plantations where vegetables and bush
tri -r.e grown. Treatment of vines with arsenicals must be
. -" made after flowering. Among fruit trees, only apples, pears, and
plums may be treated with arsenicals. Treatments must be sus-
pended during blossoming, after which they mey be made again for 15
dnys. Arsenical treatment of beets must cease one month after
transplanting.

POTTS, E. C. (145)

SPRAY TOLERANCE REGULATIONS FIXED. Better Fruit 21: 7. 1927.

All apples and pears for export in 1927 must meet the
British tolerance limit of 0.01 grain of arsenic trioxide per
pound of fruit. In 1928, all fruit, whether for export or
domestic trade, must meet this tolerance. For the 1927
season, fruit containing up to 0.025 grain will be passed
for domestic markets. .-ishing or dipping will assure
certification without further question.

STEWARD, R. F., and McKAY, C. 0. (146)

IN THE UITITED STATES COURT OF CUS0":S AND PATEIT APPEALS.
Patent Appeal Docket No. 3272. Ernest M. Brogden and Miles
L. Trowbridge, appellants, v. Arthur M. Henry, apellee.
Brief for appellants Brogden .nd Trowbridge. 88 pp. [1933?]

THOLiAS, S., MOTHERS1EAD, J. F., and PENIKHEIM, I. G. (147)

IV THE UNITED STATES COURT OF CUSTO.:S AND PATENT
APPEALS.
Patent Appeal Docket No. 3272. Interference No. 58275.
Ernest M. Brogden and Liles L. Trowbridge v. Arthur M.
Henry. Brief for party Henry, apellee. 28 pp. 1933.

UNITED STATES COURT OF CUSTOiIS AND PATENT APPEALS. (148)

TRANSCRIPT OF RECORD. UNITED STATES COURT OF CUSTOMLIS AND
PATENT APPEALS. Patent Appeal Docket No. 3272. Ernest
I. Brogden and Mjiles L. Trowbridge vs. Arthur M. Henry.
Appeal from Board of Aipeals. (Interference No. 58,275.)
625 pp. Filed Oct. 21, 19-32. Printed February 8, 1933.

7RARTON, W. R. Mi. (149)

SPRAY RESIDUES. 17. J. State Hort. Soc. Proc. Ann. Meeting
Dec. 9-11, 1925. 255 pp. (85-97.)

Excessive amounts of arsenical spray residues were found
by the Burcau of Chemistry on Western pears in 1919, on celery from
a southern State early in 1925, and on apples in New Jersey im
the fall of 1925. The activities of the U. S. DepartmEnt of
Agriculture in dealing with the situation are discussed. The
Bureau of Chemistry would make seizure of apples containing as high
as 0.01 grain of arsenic trioxide per apple.






- 40 -


III. REMOVAL OF SPRAY RESIDUES FROM FRUITS AID VEGETABLES

A. Processes


ANONYMOUS (150)

WARNING ABOUT CELERY SPRAYING. Market Growers Jour. 18: 339.
1916.

Celery growers are being warned again by the Department of
Agriculture that in spraying celery with bordeaux mixture care
must be taken to see that copper is not left upon the celery. The
consumer is advised, in cases where there is any reason to suspect
an accumulation of copper, to break up the bunches and scrub the
stalks thoroughly.

-. (151)

I..' RZESIDUE RIMCVER. Better Fruit 21 (8): 22. 1927. Also in
the Farm. Jour. 51 (4): 16. 1927.

W. P. Headden has developed a method of removing spray residue
from apples by treating for 10 minutes in a solution of 4 lbs. of
soda ash end 4 Ibs. of table salt in 100 Ibs. [sic] of water at
100F., then rinsing.

---- (152)

REIO10VAL OF ARSEHTICAL SPRAY-RESIDUE FROM FRUIT. A PRACTICAL
METHOD FOR THE FRUIT GRO7ER. Farming in So. Africa 2: 473,
4S3. 1927.

Place all fruit showing spray stains in split cane bushel
baskets and dip each basket up and down for 1-1/2 minutes in
a wooden trough containing a solution of 2 percent actual
hydrochloric acid. Then drain for a few seconds and immediately
dip vigorously up and do'xn for 2 or more minutes in a n'ooden
trough of cold, clean, and preferably running water.
(153)

REMOVING SPRAY RESIDUE. Calif. Cult. 68: 216. 1927.

Quotes from H. Hartman and R. Robinson in Better Fruit.
(See reference 249.)


REMOVAL OF SPRAY RESIDUE FROIMi PEARS AND APPLES. NOTICE TO (154)
FRUIT GROWERS. So. African Fruit Grower 15 (1): 5. 1928.

F. W. Pettey is quoted. Five methods of treatment
with hydrochloric acid for the removal of arsenic P.re given
-*vhich differ only in the strength of ncid and time of sub-
mergence of fruit. The most effective is as follows:
Submerge fruit 3 minutes in 1 percent hydrochloric acid







- 41 -


(actual hydrochloric acid). Drain fruit 1 minute. Submerge fruit
4 minutes in clear running uater. If water is limited and still
water must be used for rinsing, an American writer advises the ad-
dition of 1 pound of bicarbonate of soda to every 100 gallons of
rinse water to partially neutralize the acid.

(155)

DIVISION' OF CHEMISTRY. THE SPRAY RESIDUE SITUATION. Calif. Dept.
Dept. Agr. Mo. Bull. 17: 467. 1928.

A readjustment of wiping machines has effected an improve-
ment in spray residue removal and little difficulty is being experienced.
If the tolerance:on domestic shipments were the same as on export ship-
ments, there v7ould be considerable difficulty in meeting it in many
cases.

(156)

THE FIOLE:Li OF SPRAY RESIDUES ON APPLES. Amer. Agr. 122 (20): 648.
1928.

Summary of an article by H. C. McLean in the N. J. State Hort.
Soc. irews.

(157)

ACTUAL RESULTS [IN] SPRAY RESIDUE REI.;OVAL. Better Fruit 22 (8): 19,
27. 1928.

Reports from a number of fruit packing companies arc quoted.
Hydrochloric acid was emplcN'ed in washing the apples, usually 1
gallon to 100 gallons of water, and gave satisfactory results.

(158)

RELOVAL OF SPRAY RESIDUES. Farming in So. Africa 3: 835, 83. 1928.

A summary is given of results obtained in experiments con-
ducted in 1928 by Dr. F. W. Pettcy and Col. Rose for the removal of
spray residue from pears and apples by treatment with hydrochloric
acid solutions. 7ith few exceptions, submergence of pears for 2
minutes in 1 percent actual hydrochloric acid, draining 1/2 to 1
minute, and rinsing in plenty of practically clean water for 2
minutes at ordinary tap water temperature will effectively remove
arsenical spray residues without injury. Apples may be submerged
for 4 to 5 minutes in 1 percent acid if necessary to remove the
spray residue, but this long period is generally unnecessary unless
the fruit has been heavily sprayed or has been stored for some time
or unless the solution is considerably below 70 F. Then increasing
the temperature of the acid solution to 80 F. will facilitate the
removal.






- 42 -


(159)

INJURY TO PEARS BY HYDROCHLORIOAflID OLUTTI01T., Farming in- So. Africa
3: 875, 901. 1928.

F. W. Pettey states that two types of injury may result from
treatment of pears for the removal of spray residue by submerirng
them in a weak solution of hydrochloric acid. One type consists of
the collapse, nd blackening of the lenticels of the skin of the
fruit and the other consists of the burning of the skin area which
turns brown.

(160)

THE SPRAY RESIDUE PROBLEM. Calif. Cult. 73 (15): 360-361.
1929.

Hydrochloric acid is recommended for the removal of spray
residue. The necessity of cleaning pears and apples to be dried is
emphasized as the dried fruit will contain a much larger proportion
of arsenic than the green fruit.

(161)

WASHI-IUG FRUIT TO REi:OVE SPRAY RESIDUE. Rural New Yorker 88 (5068):
1034. 1929.

A public service patent (365) for acid bath fruit washing has
been issued to H. Hartman and R. H. Robinson of the Oregon Experiment
Station.

(162)
SPRAY RESIDUE OiT GRAPES. Rural F'ew Yorker 89: 1079. 1930.

Dipping bunches of r;apes in a solution of 1 gallon of concen-
trated acetic acid ii 100 gallons of water is recommended for the
removal of spray residues.

(163)

ABOUT SPRAY RESIDUES. Fruits and Gprdens 26 (6): 6. 1930.

E. V. Shear has found that very dilute hydrochloric acid
irmncdilately followed by rinsing with water gives the best results in
removing spray residue, from fruit.

(164)

SPRAY RESIDUES. Hoosier Hort. 13: 183-186. 1931.

The information presented on fruit washing is taken from the
U. S. Dept. Agr. Farmer's Bull. 1687 (217), to which the reader is
referred for further details.






- 43 -


----- (165)

HO TO KE1OVE SPRAY RESIDUE. Amer. Agr. 127: 218. 1931.

Arsenical spray residue is removed from apples by washing
them "!ith a solution of 1-1/2 to 3 gallons of hydrochloric acid
(20 Be.) in 100 gallons of water.

------ (166)

SPRAY RESIDLE REMOVAL. N. J. Agr. 15 (5): 4, 5. 1933.

The use of a wetting nnd degumming aLent in conjunction with
hydrochloric -acid, as developed by H. C. McLean, is successful in
removing spray residue from .fruit treated with oil-lead arsenate
sprays.

---- (167)

SPRAY RESIDUE OT VEC-ET;LES. Market Growers Jour. 52: 139. 1933.

The method commonly used in New Jersey for removal of arsenic
residue on vegetables is submergence in 1 percent hydrochloric acid.
Vinegar solution has been used by a Pennsylvania gardener.

----- (168)

REiiOVING ARSE'-ICAL RESIDE FRCL. APPLES. Agr. Gaz. N. S. Wales 45:
147-148. 1934.

SDipping apples in 1 1/2 percent hydrochloric acid solution
removed 90 percent of the arsenic from apples sprayed with lead
arsenate alone (0.0767 grain arsenic trioxide per pound was the
moan of the undipped fruit). Sodium carbonate solutions were only
2 rcrcent less effective than the hydrochloric acid in removing the
lead arsenate alone. Hydrochloric acid (1 1/2 percent) removed only
78 percent of the arsenic from apples sprayed with white oil combined
with lead arsenate, and sodium carbonate solutions were even loss
effective.

ABILDG-AARD, W. (169)

THE V:.Yf AiTD HOW OF FRUIT HASHI-ITG. Neb. State Hort. Soc. Ann.
Rpt. 61: 102-106. 1930.

Under ordinary conditions, a solution of 5 to 7 qts. of
commercial hydrochloric acid to 100 gals. of water is sufficient
for removal of lead arsenate spray residue from apples. Late in
the season it is sometimes necessary to increase the concentration
to 10 or 12 qts. per 100 gals. of water. Hydrated lime is sometimes
used in the rinse water, especially when water for rinsing is not
available in abundance. One to 2 lbs. of hydrated lime per 100 gals,
of rinse water is generally used.








-44-


------ (170)

THIS FRJIT WASr-IITG QUESTION. Amer. Fruit Growers 50 (12): 4, 13.
1930. Part II. Ibid. 51 (1); 7, 23-24. 1931.

The history of the arsenical spriy residue situation and
the development of fruit washing with dilute hydrochloric acid are
discussed.

(171)

THM1 REMOVAL OF DIRT AND SPRAY PESIDUE FROM FRUIT. Pa. State Hort.
Assoc. News 8 (1): 33-37. 1931.
Washing of apples greatly improves the appearance by removing
dirt and insect residues as well as spray residue.

ALLEN, L. R. (172)

A GROWER'S EXPERIEiCES AND VIEWPOINT. ll. State Hort. Soc. Trans.
64: 175-177. 1930.

A brief description of the method of washing fruit for the
removal of spray residue, as described in U. S. Dept. Agr. Circ.
59 (214).

3AIER, K. H., and HEALD, F. D. (173)

SOi.IE PRCFLEI.S COUCERITITG BLUE I)'LD IN RELATIC7 TO CLEANING ATID
PACKING OF APPLES. Phytopathology 22: 879-898. 1932.

The toxic action of 3 percent hydrochloric acid, and of
sodium carbonate-borax cleaner at a concentration of 1 1/2 Ibs.
per gal and of sodium carbonate-trisodium phosphate cleaner at a
concentration of 60 lbs. per 100 gals. on spores of Penicillium
exparnsum (blue mold) is of a slow type, and no action would occur
on spores on apples during their brief exposure in washing. The
cleaners as used at present [1932], however, will keep the tan':s
reduced to a concentration of viable spores whose maximum will be
that accumulated in a day's run.

JALLAiTYVE, J. A., and CAYZER, L. S. (174)

REi2OVAL OF ARSENJICAL RESIDUE -FRO.: AFFLES. Agr. Gaz.-N. S. ">les
43: 459-466. 1932.

Where oil sprays have been included in the spray program as
a substitute for the late covers of lead arsenate, less arsenic is
present on the harvested apples. In all cases where oil sprays
have been used, less arsenic can be removed from the fruit. The
arscnical residue on apples which have received as many as 6 spraying
of lead arsenate can be reduced to an amount within the world tolerance
by dipping in 2 percent hydrochloric acid. At a temperature of 70 F.,






- 46 -


1 percent hydrochloric acid is not suitable for the removal of the
residue, Two percent acid is satisfactory, but any further increase
in strength does not result in a proportional advantage. Certain
varieties of apples (Statesman, Senator, Kentucky Red Streak,
Delicious) which have had identical treatment in the field, when
harvested differ considerably in the amounts of arsenical residue
rcseont. The wax formed on the apples during storage hinders the
solvent action of the acid. Apples should be harvested at the
correct stage and dipped immediately.

BALLARD, F. L. (175)

SPRAY-RESIDUE REMOVAL. Country Gent. 93 (8): 42. 1928

In Oregon, arsuni'0-l residue h?.s been removed from apples and
pears by washing with weak solutions of hydrochloric acid. Formalde-
hyde used in the acid bath keeps it free from many decay spores.

BAIROI, J. A. (176)

0CL EXIZRIENCES IIN APPLE WASHING. Ill. State Hort. Soc. Trans. 64:
169-175. 1930.

The results of experiecas In wiping and washing with hydro-
chloric acid (2 gals. 18 percent commercial acid to 100 gals. water)
are reported. Apple washing was found to be neither expensive nor
difficult.

----- (177)

THIS FRUIT WE"T TO THE LAUTNDRY. Amer. Fruit Grower 50 (6): 6, 17.
Illus. 1930.

The experience of a packing company in 1929 in washing apples
with hydrochloric acid (2 gals. commercial acid to 100 gals. water)
in a commercial fruit washer is described.

BEAUL01T, J. H. (178)

SATISFACTORY WASHING i";ETHCDS FOR SPFLAY RESIDUE REMOVAL IN THE EAST.
V:d. Agr. Soc. Rpt. 19: 180-186. 1935.

Because of fewer codling moth sprays, the use of fungicides
in most of the summer sprays, the occasional use only of stickers
and summer oils, and a greater summer rainfall, there is a more
moderate spray coating on fruit grown under eastern conditions and
one more easily removed to the tolerance by the simpler washing
methods. Injury to washed fruit is most likely to follow ineffective
rinsing. A supply of at least 1 to 2 gals. of fresh water per bu.
should be provided for rinsing off all acid and soluble arsenic. If
sufficient water ia not availrpblo, acid in the rinse tank must be







- 46 -


neutralized by adding pulverized limestone. The speed and efficiency
of the reaction between the hydrochloric acid wash solution and the
arsenic and- lead residues on the fruit depend on a number of factors;
notably, the amount and character of the residue, the concentration
of the acid, the temperature of the solution, the time of exposvrc,
and the presence of a wvetting agent.

Lead residues not combined with mineral oil and not exceeding
0.066 grain per lb. may with reasonable certainty be removed with cold
0.5 percent acid in a flotation machine with 1 minute exposure, and
similar residues not exceeding 0.10 grain per lb. may be removed with
1.5 percent acid under similar conditions. Lead residues exceeding
0.10 grain per lb. or when combinred with oil may be expected to re-
quire more complex treatment. The effectiveness of.the acid bath
may be increased by heating and by the addition of a wetting agent,
such as Vatsol. When washing has been delayed for a week or more
after harvest and the fruit has developed a heavy wax or bloom, heat-
ed solutions, wetting agents and perhaps even sodium silicate may be
necessary to remove the residue. The size of the fruit may also have
considerable bearing on bringing the residue to the tolerance, be-
cause small apples, having a greater surface per unit weight, will
gcncrally carry a heavier coating Of residue. Any type of washing
machine most suited to the growers' requirenents can be used, but
considcor-tion must be given to the gentleness of hpnrdling the fruit,
to the flushing and rotation of the fruit in the acid tank and to
the rinsing of the fruit.

EA10I:T, J. H., and kALLEx, ivM. H. (179)

RELATIVE VALUE OF 2. '-:` AL Y2TIiNG AGEZATS IN FEMOVI1G LEAD RESIDUES
FROMi APPLES. Anor. Soc. HIort. Sci. Proc. 32;183-189. 1935.

Seven wetting agents wore tested at a concentration of 1 per-
cent in 1-1/2 percent .ydroc'hloic acid at 70cF. a,. ICOF. c.nd in
the sane solution plus 1 prc nb salm t at the E-e* tn.cr- tures.

The authors prc sent the following conclusions:

1. Of the wetting agents tested for their value in facilitating
the rcrwcoval of load residues, Igcpon T and Hydrin A had no beneficial
effect. Ak.1oniun Sulfosoap was inter-ecdiate, and Vatsol, Ares:at,
Nekal B and DuPont No. 2 were quite effective. DuPont No. 2 and
Areskat caused injury at a temperature of 100 F. to a sample of
York Imperial apples that were sprayed with seven cover sprays of
lead arsenate, the last four covers containing 1 gal. of mineral
oil per 100 gals.

2. An increase in the temperature of the wetting agent
solution from 70 to 100 F. was tremendously effective in in-
creasing the efficiency of the wash.






- 47 -


3. The fish and. mineral oils used with lead arsenste affected
the residues at harvest and also the removal of the residues by the
wetting agent solutions. The solutions on the average removed both
types of residues equally successfully.

4. One percent of salt had no effect whatever in the wetting
agent solutions.

5. The interaction of wetting agent and temperature was not
significant and indicates that these factors were purely additive
in increasing the efficiency of the washing solution.

BENTON, R. J., and POWELL, T. N. (180)

REMOVING BORDEAUX SPRAY FROM ORANiGES. Agr. Oaz. N. S. Wales 44:
683-684. 1933.

Hydrochloric acid, from 1/8 to 2 percent, was found satis-
factt7ry for the removal of residual bordeaux spray on oranges.
The fruit is dipped in the acid and then in fresh water. Dipping
in 1 percent sodium sulphate or sodium chloride, in addition to
the acid alone, was of no advantage. Acetic, lactic, citric,
and tirtaric acids also readily removed the discoloration due
to tho bordeaux mixture but hydrochloric acid was the most satis-
factory and economical solvent.

BOUR3E, A. I., and ROBERTS, 0. 0. (181)

THE PROBLEM OF SPRAY RESIDUE. Mass. Fruit Growers' Assoc. Rpt.
of 34th Ann. Cony., pp. 101-109. 1928.

Mechanical wipers were in many cases ineffective in remov-
ing spray residue to the required tolerance. Dilute hydrochloric
acid (about 1 percent) and a few other substances give promise as
solvents. Calcium caseinate in sprays has a tendency to increase
the amount of arsenical residue present. Apples should not be
sprayed with lead arsenate within 6 weeks of the time of harvest
and calcium caseinate should be omitted from the latest sprays.
Dusting can be carried out later than spraying.

BREGGER, J. T. (182)

SPRAY RESIDUE SITUATION. Better Fruit 25 (1): 9. 1930.

Dry wiping of fruit is not sufficient for residue removal
when three or mrro cover sprays have been applied. Hydrochloric
acid is the solvent most generally used in fruit washing, A two-
thirds of one percent solution is ordinarily effective, but with
heavier residues caused by an oil and lead combination this amount
is usually insufficient. The efficiency of hydrochloric acid has
been increased by the use of iron salts, sodium sulphate, and
common table salt. The last seems most effective. Hydrochloric








- 48 -


acid may be used up to 1-1/3 percent (4 gals. to 100 gals. water).
Waxy fruit may be treated first with kerosene emulsion (kaolin
emulsifier) to remove "the wax. Early cleaning is easiest. Alkaline
washes are occasionally used instead of acid.

----- (183)

THE APPLE SPRAY RESIDUE SITUATION. Amer. Fruit Grower 53 (5):
5-6. 1933.

The latest Federal residue tolerances are: arsenic 0.01
grain per pound of fruit, fluorine 0.01 grain per pound, load
0.02 grain per pound. Present washing solutions do not remove
lead in the same proportion as arsenic. Either lead substitutes
must be used in spraying or revised washing methods must be found
which will satisfactorily remove the spray residue.

SRIIITOI, C. S. (184)

THE SPRAY RESIDUE PROBLEM IIN ELAWARE. Del. Bd. Agr. Quar. Bull.
20 (5); 74-81. 1931.

In'the future undoubtedly heavier applications of lead
arsenate will have to be made and all apples will have to be washed.
The v'orld tolerance will be in force for domestic shipments within
a year or two. Dipping in weak muriatic acid followed by rinsing
is recommended as a cleaning method.

.tOCKe. w (185)

APPLE WASHITG PROBLEM,. Ia. State Hort. Soc. Rpt. 1930: 137-140.

The history of the spray residue situation is sketched.
Washing with hydrochloric acid (3/4 to 2 percent) is recommended
for the removal of arsenical residue.

BRO, C. L. (186)

STRICTER RULES FOR SPRAYS. Country Gent. 103 (9): 54. 1933.

For the removal of arsenic residue alone, alkali solutions
appear most effective; for lead arsenate weak hydrochloric acid
is believed more efficient.

BURKHOLDER, C. L. (187)

THE PROBLEM OF SP-RAY RESIDUE REMOVAL FROM THE FRUIT GROWERS' VIEW-
POINT. Mich. State Hort. Soc. Ann. Rpt. 61: 70-74. 1932.

Switching from lead arsenate to oil sprays after July 1, on
Ben Davis apples, in 1931, did not reduce the arsenical load at
picking time. Increasing the strength of acid above 1 percent by




- 49-


volume in the dipping tank method failed to give enough better
results to 7arr?-nt the practice. Using 2 percent acid in a
brush typ Bean washer, two-thirds of the original arsenical
load vMs removed on the average. The dipping tank method
averaged only 50 percent removal.

------ AIM FORD, 0 t. (188)

BASHINGG APPLES TO REMOVE RESIDUE IN 1931. Hoosier Hort. 14:
107-111. 1932.

The brush type washer can be depended on to remove about
two-thirds of the arsenical load present. Increasing the
strength of hydrochlorie acid wash solution from 2 to 3 per-
cent uy volume did not Increase the percentage of arsenic
removed with a cold solution. A cold wash of 1 oz of sodium
metasilicate per gal, was slightly less efficient than 2 or 3
perc-nt cold hydrochloric acid. Cold sodium metasilicate plus
a Ec -.r emulsifier gave a higher percentage of removal than' hot
(900 1.) sodium metasilicate without emulsifier. Hot (90 Fr)
2 percent hydrochloric acid fbhwed a slight increase in efficiency
as compared to cold 2 percent acid.. The advantage was toe slight
to warrant the extra expense and labor of adding heating equipment
to the washer.

-- and POB, 0. 7. (189

1931 ANH 1932 RESIDUE AND WASHER RESULTS FROji PURDUE FARM, EDiORD.
Hoosier Hort, 15: 68-70. 1933.

Cold 2 percent hydrochloric acid gave as good removal of
arsenical spray residue as any of the materials tried (others
were hydrochloric acid at 90, hot (90) and cold sodium metasilicate,
4 percent hydrochloric acid, and hydrochloric acid plus soap
emulsifiers). Very little difference in arsenical load at harvest
or in cleaning effi-ciency of 2 percent hydrochloric acid resulted
when 1 or 2 percent oil sprays wore used in place of ri gUlar sprays
for second-brood applications.

--..-.. and FORD, 0. 17, (190)

WASHING APPLES TO REMrOVE E2SIDUJ IN 1931. Ind. Hort. Soc, Trans.
1931; 64-72. 1932. Ind. Hort. Soc. Trans. 72t 124-127. 1932.
Hoosier Hort, 14 (7): 107-111. 1932,

Increasing the strength of hydrochloric acid from 2 percent
to 3 percent by volume did not increase the percentage of arsenic
removed with a cold solution. A cold wash of 1 oz. of sodium
metasilicate per gal, of water was slightly loss efficient than
either 2 or 3 percent cold hydrochloric acid. There was some
indication that a soap emulsifier added to the cold sodium
metasilicate Solution slightly increased the removal. Cold







- 50 -


sodium metasilicate plus emulsifier gave a higher percentage of
removal than hot (90OF.) sodium metasilicate without emulsifier.
Hot (900) 2 percent hydrochloric acid showed a slight increase
in efficiency as compared to cold, but the advantage was so slight
that it did not warrant the extra expense and labor of adding heat-
ing equipment to the washer.

---- and FORD, 0. W. (191)

THE 1934 SPRAY RESIDUE SITUATION IN INDIANA. Hoosier Hort. 16 (7):
99-101. 1934.

Under the schedule and weather conditions of 1933, the arsenic
load v-is cleaned to well bcloiwr the tolerance with 3 purc.nt by volume
hydrochloric acid. All other treatments were also well below 0.01
grain arsenic trioxide per pound except samples run through a dry
cleaner. All samples run through the ,cid averaged just 0.02 grain
of lead after washing. Waxy varieties were not cleaned to 0.02.
Samples run through acid alone at 100 barely met the 1934 tolerance
of O.C19. In other 'ords, a 30-second exposure at higher tempera-
tures did not increase removal to any worthwhile extent. Three per-
cent acid by volume plus 6 lbs. of Vatsol to 100 gals. at 65 F. re-
sulted in removal to just below the 1934 tolerance. This wash at
100 F. showed only slight increase in removal over 65 F. Of the
defcoming agents used, coconut oil burned the fruit and sulphonated
coconut oil left the fruit sticky even after 5 months stora,e. Do-
foamer No. 16, a naptha-wool grease combination, reduced foaming
satisfactorily and did not injure the fruit.

----- and F-RD, 0. r. (192)

NOTES ON 1934 APPLE VTASHING WHICH ARE OF SPECIAL INTEREST TO
INDIANA GROWERS. Ind. Hort. Soc. Trans. 1934: 85-91. 1935.

Four types of apple washing equipment were studied during
1934; (1) a new mcLel X flotation washer, (2) a new model E under-
brush-flood washer, (3) tandem washing with hot sodium silicate and
a wetting agent in a specially constructed underbrush washer, follow-
ed by acid in the model X flotation washer, and (4) a dual washing
treatment in which hot sodium silicate and a wetting agent were used
in a home-made flotation unit followed by a 20-second exposure to
acid in a flood type washer. Equipment no. (2) was very efficient
in residue removal; with 1 1/2 percent acid plusal percent Vastol,
the percentage removal on load-oil sprayed Wincsaps carrying 0.3297
grain of lead per lb. was 85 percent for 20 seconds. exposure at
110 P., and 93 percent for 30 seconds; with 2 percent acid it was
88 percent for 20 seconds and 91 percent for 30 seconds. When
treatment no. (4) was used, preceded by a dry cleaning and allowing
1 1/2 minutes' exposure to sodium silicate and 1 percent Vatsol at
90 to 108 followed by 30 seconds' exposure to cold 1 1/2 percent
acid in the flood-type washer, a lead removal of 90 to 97 percent
was consistently obt-.ined. All samples analyzed for this method





- 51 -


were run within 24 hours after picking. Method (3) could be
depended on to give 80 to 85 percent lead removal on Winesaps
carrying a lead load of 0.3297 grain and held for 2-1/2 weeks,
when 75 lbs. of sodium silicate plus 1/4 percent vatsol for 30
to 40 seconds was followed by cold 1 1/2 percent acid for 2
minutes.

BL.TIER, c. C. (193)

THE SPEAY EESIDUE PROBLE4. Amer. Fruit Grower Mag. 47 (8): 5,
13, 17. 1927.

The development of the spray residue situation from 1921,
when Boston made some protest on the subject, up to the time of
writing is outlined. The recommendations of R. H. Robinson and
H. Hartman on spray residue removal (363) are summarized.

CAITE-R, PI. H. (194)

AN I-:ESTIGATIOV OF SOL.TIENTS 70F.O THE RJICVAL OF LEAD A-L3E."ATE
RESIDUES rHO:.i FRrUIT. Jour. Econ. Ent. 27: 848-853. 19-4.

Most of the common inorganic acids are apparently strong
enough to attack lead arsenate to a greater or less degree.
Those acids which furnish ions capable of forming soluble salts
with both 1 ad and arsenic exert a true solvent effect. h:'rdro-
chloric acid is the best in this respect. Those acids which
furnish ions c-p' .ble of forcing insoluble lead salts (such as
sulphuric and chromic) are capable of dissolving more arsenic
but a smaller amount of lead.

Organic acids are apparently too weak to exert a solvent
action on lead arsenate but are capable of undergoing reactions
with it, causing precipitation of insoluble lead salts.

Solutions of salts alone or "'hen mixed with acids to
not have an .ppreciable solvent action unless they also cause
reactions forming other insoluble compounds. A high concen-
tration of sodium chloride in hydrochloric acid may be of benefit
in dissolving lead chloride.

Some of the alkalines, especially sodium silicate and
sodium hydroxide, are capable of dissolving appreciable quanti-
ties of both le-d and arsenic. Weak alkalies, such as ammonium
hydroxide and organic amines, do not have appreciable action.

The ad ition of salts to solutions of alkalies may be
of some benefit and offers a field for further investigation.

The use of wetting agents and degumming soaps may be of
some benefit in removing lead arsenate spray residues through
the physical action of increased -.,ettability but probably do not
have much solvent action per se.







- 52 -


-- ..(195)

SOLVENTS FOR CRYOLITE. Jour. Econ. Ent. 27: 863. 1934.

Sodium chloride decreases the solubility of
cryolite in dilute bydrochloric acid. Sodium chloride,
sodium bicarbonate, and monosodium phosphate each d-crease
the solubility of cryolite in water at 20 C. Several com-
pounds, including boric acid, aluminum salts, and ferric salts,
increase the solubility of cryolite in 1.5 percent' hydro-
chloric acid (1.5 g. HC1 per 100 cc.) and in water.

CHAPMAN, P. J., (19 6)

TH.E APPLE MAGGOT. N. Y. State Hort. Soc., Proc. 76th Ann.
Meeting, pp. 201-210. 1931.

The washing machines using 1 or 2 gals. of commercial
hydrochloric acid in 100 gals. of water may be expected to
satisfactorily reduce the arsenic in residues now [1931]
encountered in New York. Dry cleaners improved the appearance
of the fruit by removing dust and sulphur residues, but are less
efficient than washers in arsenic removal, hardly removing
one-third of the poison. The desirable machine should in-
clude the principle of an acid wash for arsenic removal in
conjunction with the brushing or wiping principle for the
removal of dirt, the bnlackened honeydew associated with
aphis and pear psylla, and the spotting from leaf-hoppers.

----- and PEARCE, G. W. (197)

THE SPRAY RESIDUE PROBLEM OF CURRANTS. N. Y. State Hort.
Soc. Proc. 1935: 250-265.

It is more difficult to reduce lead to the tolerance than
arsenic. In view of this, one might well consider using
calcium arsenate in place of lead arsenate on the fruit trees
in currant plantings. Stemming of currants removes a con-
siderable amount of the spray residue. Immersion of currants
in 1 percent hydrochloric acid for 2 to 3 minutes, followed by
thorough rinsing in clean water, is recommended.

Jelly made from currants bearing approximately 3
times the tolerance for arsenic and 5 times the tolerance
for lead contained well below the legal limits for both
materials. Two lots of fruit analyzirng 0.01 grain of
arsenic trioxide per pound yielded juice analyzing 0.006
and 0.004 grain of arsenic and 0.007 and 0.008 grain of
lead per pound, respectively.






- 53-


CHILDS, L. (198)

THE PROBLEM OF ARSEVICAL RESIDUES: THE SITUATION IN
DIFFERENT APPLE-GROWING AREAS AIOD RESULTS OF INVESTI-
GATIONS RELATIE'TO O THE PRODUCTION OF 'APPLES TO MEET
MAHCET REQUIREJ.iENTS. 4th Internat. Congr. Ent., Ithaca,
Aug. 1938, pp. 675-687. 1929.

The history of the arsenical spray residue problem
is given. Generally speaking, fruit washed immediately
after harvest can be reduced within 30 seconds to 0.01 grain
of arsenic trioxide per pound with a concentration of 1
percent commercial acid (0.33 percent actual acid) with'jet
and flood wash machines.

CLABKE, J. O. (199)

ADMINISTRATIONiOF1* THE RESIDUE TOLERANCE. Ill. State Short.
Soc. Trans. 64: 154-169. 1930.

A general discussion of the spray residue situation.
Washing of apples with hydrochloric acid is recommended. On
42 samples so washed, the arsenic before washing ranged
from 0.040 to 0.002 grain and afterwards from 0.019 to a trace.
Only one sample was above the domestic tolerance and 3.above
the world tolerance after washing.

COHEE, R. H., and ST. JOHN, J. L. (200)

LEAD URSOLATE IN.RELATION TO FRUIT CLEANING. Indus. and
Engin. Chem. 26: 781-782. 1934.

Lead ursolate was prepared from ursolic acid
isolated from apple wax. This salt is insoluble in 1.5
percent hydrochloric acid and slightly soluble in 10
percent sodium silicate. Interference of wax in fruit
cleaning may be due, in part at least, to the formation of'
such a compound on fruit sprayed with lead arsenate. Evidence
of the presence of an organic lead compound on sprayed fruit
is presented.

The solubility of lead ursolate in 10 percent sodium
silicate is increased by the addition of 1 percent of chloro-
form, benzene, toluene, or xylene. The results obtained may
help to explain the lack of relation noted between the solu-
bility of lead arsenate in different .nashing solutions and their
relative effectiveness in actual fruit cleaning.

COWPER, E. G ; (201)

THE SPRAY RESIDUE SITUATION. Amer. Agr. 130: 259. 1933.

As early as 1919, the U.S. Department of Agriculture made







-54-


detentions of western :apples containing excessive amounts "of
spray residue. In 1925 and 1926 a great deal of western fruit
was detained* Investigations Started about this time showed
that a dilute hydrochloric acid wash was very effective for
the removal of arsenical residue. Some baths, such as tri-
sodium phosphate, effectively remove arsenic but have no
effect on lead. Both lead and arsenic are cumulative poisons.
Efforts are being made to find a substitute for lead arsenate
as a spray material.

COX, A.J. (202)

FACTS CONCERNING THE SPRAY RESIDUE PROBLEM PERTII3ENT TO THE
FRUIT AND VEGETABLE INDUSTRIES. Calif. Dept. Agr. Mo.
Bull. 22: 389-396. 1933.

There is a growing demand for more rigid enforcement
of the spray residue law. Washing of appl s and pears with I
percent hydrochloric acid plus 1 to 2 percent ordinary salt at
100 to 1100 F. is recommended for removal of arsenic and lead.

---- (203)

CALIFOGR]IA SPRAY RESIDUE PROBLEMS. Pacific Rurrl Press 127:
166, illus. 1934.

Wiping or brushing methods of cleaning fruit cannot
be depended upon to remove more thhn a small part of the
poisonous. residues. Simply washing in water has very little
effect on spray residue. Hydrochloric acid has proved to be
the most satisfactory washing material. In general, a con-
sistently maintnind 1 percent solution of hydrochloric acid
(3 gals. commercial acid to 100 gals. water) at 100 to 1100
F., with 1 or 2 percent common salt (8 to 16 lbs. to 100 gals.
solution) will suffice for Pdequate remova-l of spray residue
in 40 seconds under California conditions. The acid wash should
be followed by thorough rinsing in clean, fresh water and, if
possible, a fresh 7r.ter spray. Fruit may be tested for freedom
from acid as it loaves the rinse water by placing the corner of
a small piece of litmus paper into the calyx. If the paper turns
red quickly, the rinsing is inadequate.

COX, W. T. (204)

REMOVAL OF SPRAYING RESIDUE. Rural New Yorker 90: 343. 1931.

A brief general discussion. Washing with hydrochloric
acid, 1 gal. to 100 gals. of water, is recommended.








- 55 -


DE SELLER, F. E. (205)

WASHING APPLES rITEH.BW SODIUM SILICATE. Wash. State Hort.
Assoc., Proc. 29th Ann. Meeting 1932: 124-127.

B,.' sodium silicate 7-is romp'oyed, at concentrations
ranging from 53 to 130 lbs. per 100 gals. of water, to clean
apples. It can be used at temperatures of 115 to 120 F.
without injury to the fruit. The cleaning efficiency is in-
creased when foaming occurs. The waxier the fruit, the more
easily it is cleaned. The efficiency apparently increases
after a number of boxes of fruit have passed through the
solution. Twelve thousand looze boxes have b;:en washed
without having to dump the solution. B7 sodimn silicate
does not break down as quic'-:1y rs the other alkalies (soda
ash and trisodium phosphate).

DIEHL, H. C. (206)

SUGGESTIONS DERIVED FROM SPAY P2IDUJE RE0'OVAL EXPERIEiCES
OF 1927 SEASON. ?otter Fruit 22 (12): 13-14, 18-19. 1928.

Dry cleaning is less satisfactory than washing. The
concentration of hydrochloric acid used in washing should be
at least one gallon to the hundred. The solution should be
Unrmcd to et least 80 to 85 F., preferably 90 to 100.

(207)

LEAD AP.SEIATE OIL SPRAYS AND RESIDUE ?E::0VAL. Wash. State
Hort. Assoc. Proc. 25: 69-88. 1929.

The following measures are reco.mmended to reduce
lead arsenate residues on fruit: (1) Avoidance of so-called
heavy oils in spraying. These are oils with high viscosity and
low volatility and when ustl with lead arsenate made residue
removal very difficult. (2) Reduction of the load of lead
arsenate on frait as much as possible without sacrificing con-
trol, by using substitute insecticides or supplementary methods
of control. (3) Combination lead arsenate-oil sprays should not
be applied to fruit closer to harvest time than from 4 to 6
weeks. (4) Avoidance of the application of oil over blotched
deposits of lead arsenate on fruit.

The addition of sodium chloride and sodium sulphate
to warm dilute acid solution facilitated the removal of
lead arsenate residues. The addition of kerosene emulsion
is also helpfIl with apples difficult to clean. Other
materials, such as toluene and benzene emulsions, ethyl
and methyl alcohol, and similar solvents are being tested.

Voluminous data on fruit washing are presented in
tabular form.






- 56 -


---- (208)

SPRAY RESIDUE REMOVAL F2OM APPLES A!-D PEAS. Fruits and
Gardens 28 (8): 6-7, I0-i. 1930.

The use of hydrochloric acid, at least 1 gal. of
commercial acid to 100 gals. of water a.nd not more than 4 gals.
to 100 gals. is recommended. Heati-ig to at least 800 to 85 F.,
and to 90 or 1000 for fruit difficult to clean, greatly in-
creases the efficiency of the operation, enabling the acid con-
centration to be lowered. The a-ldition of salt to the washing
solution often enhances its ffi'"iency. Kerosene emulsion
prepared with kaolin aids in cle':,ni.ng fruit which has been
treated with a spray containing oil and lead arsenite. Thorough
rinsirng is important to prevent soluble arsenic injury and decay.
If fresh rinse water only cannot be used, the addition of lime
to it will neutralize the acid carried over by the fruit and
render insoluble any remaining arsenic.

---- (209)

SPRAY RESIDUE REMOVAL 3Y LATEST 1,1THGDS IS AN ECC'IO1IC
BENEFIT. Yearbook of Agr, 1931: 484-487. 1931.

Dry cleaning is not generally satisfactory for
removing excessive arsenical spray residue. Washing
methods employing hydrochloric acid are by far the most
frequently used, although alkaline materials may also be
employed. The latter are generally efficient, but because
of the solvent action of alkalies upon the waxy coating
of the fruit, their use must be supervised rather closely,
particularly the rinsing phase. Simple dipping methods are
relatively inefficient.

The satisfactory washing of apples and pears generally
requires an -icid concentration of at least 1 gallon to 100
gallons of water. The commercial grade of hydrochloric or
muriatic acid is used. The time required to remove spray
residue depends upon the variety and maturity of the fruit,
the amount of residue present, the strength and temperature
of the acid solution, and the method of application. The
addition of common salt to the acid solution will often en-
hance its cleaning efficiency, particularly if the solvent
is warmed. One percent salt by weight dissolved in the
washing solution has generally been sufficient. The use of
2 or 3 gallons of fresh water per bushel of fruit is desirable
for rinsing.

---- EZELL, B. D., and RYALL, A. L. (210)

SOC.E FACTORS IN SPRAY .ESIDUTJE REMOVAL. Better Fruit 23 (9):
9-11, 24, 26, 28. 1929.


Diffused spray, stream wash, flood wash, flotation, and





- 57 -


modified box dip types of fruit washers are satisfactory.
Th-e concentration of acid required for cleaning different
varieties increases in the following order: 17inter Banana,
Jonathan, Delicious, Spitzenberg, and Winesap. From 1-1/2
to 2 gals. of acid per 100 gals. of water for Jonathans and
2 gals. per 100 for'Delicious and later varieties is advis-
able. Warming the solution increases the ease of cleaning.

---- EZELL, B. D., and RYALL, A. L. (211)

RELATION OF SCILE FACTORS IN SPRAYING AND CLEANING PRACTICES
TO EFFICIENCY OF REMOVAL. Idaho State Hort. Assoc. Proc.
34: 25-33. 1929.

Dry cleaning methods are less satisfactory for residue
removal than washing is. Satisfactory methods of applying
the solvent solution to the fruit are: (1) fan-shaped,
diffuse- spray, using either acid or warm alkaline solution,
(2) stream wash, (3) flood wash, (4) flotation, (5) modified
box dij. or certain combinations of these. Proper washing
of apples and pears generally requires at least 1 gal. of
acid per 100 gals. If the fruit is from rnnchcs where the
spray schedules have varied and some apples may be difficult
to clean, it is advisable to use 1-1/2 to 2 gals. of acid per
100 gals. as a minimum for Jonathans and at least 2 gals. for
Delicious and later varieties. In some clsf's cven higher
concentrations have been required, up to 6 gils. of icid per
100 gals., but more consistent cleaning is obtained by warming
the acid at a lower concentration when these high cold con-
centrations seem necessary, or even fail, to reduce the
residue satisfactorily.

The use of fish oil with lead arsenate and of heavy
technical oil following or preceding lead arsenate makes
cleaning more difficult.

--- and FAHY, J. E. (212)

SU,';ESTIONS FOR THE USE OF ADDITIONAL SOLVENTS FOR IIICREASIIIG
THE EFFICIENCY OF HYDROCHLORIC ACID AS A CLEA1SIEGr SOLUTION
FOR APPLES. 2 pp. mimeo., Oct. 1930.

The procedure to be used in washing apples when the
additional solvents are used which have been described by
A. L. Ryall and the authors (219) is described in greater de-
tail. From 1 to 2 percent of salt by weight and a temperature
of 90 to 100 F. are recommended for most cases. When clean-
ing is exceptionally difficult, kerosene emulsion is helpful,
but should be used only in machines providing constant agita-
tion. The emulsion is made up from 1-1/3 lbs. kaolin, 1 gal.
kerosene, and 1/2 gal. water. The use of 1-1/2 gals. per 100
gals. of washing solution is recommended.




-58-

---- and FAHEY, J. E. (213)

THE EFFECT OF FISH AND MINERAL OIL SPRAYS IN PROBLEMS OF
ARSENICAL SPRAY RESIDUE REMOVAL. Wash. State Hort.
Assoc. Proc. 27: 57-60. 1931.

Fruit receiving six cover sprays of lead arsenate with
eitlver mineral oil or fish oil could not be cleaned with 1
percent hydrochloric acid or 1 percent hydrochloric acid plus
percent salt at temperatures below 100 F. The fruit con-
taining fish oil was not cleaned satisfactorily by a solution
containing 1 percent hydrochloric acid, 1 percent kerosene
emulsion, and 1 percent salt at 100 F. This treatment did
satisfactorily clean fruit sprayed with mineral oil.' An
alkaline phosphate solution (60 lbs. trisodium phosphate per
100 gals.) at 115 F. removed residue from fruit sprayed with
fish oil satisfactorily but was not so efficient for fruit
sprayed with mineral oil.

---- FISHER, D. F., HARTMAN, H., MAGNESS, J. R., (214)
and ROBINSON, R. H.

REMOVAL OF SPRAY RESIDUE FBRDM APPLES AND PEARS IN THE PACIFIC
NORTHWEST. U. S. Dept. Agr. Circ. 59. 20 pp. 1929.

General aspects of spray-residue removal, cleaning
fruit by wiping or brushing, and cleaning fruit by solvent
methods are discussed. The dry-cleaning methods, under
the best conditions, do not consistently remove from apples
more than about 30 percent of the spray residue on the fruit
when the uncleaned fruit shows not more than 0.04 grain of
arsenic trioxide per pound.

Various types of washers are discussed. Hydro-
chloric acid was used for cleaning in most cases. The
amount of acid necessary was less at higher temperatures.
In many cases 1 or 2 gals. of acid to 100 gals. of water was
sufficient if the solution was warm. A warm alkaline solution
was also employed in cleaning fruit in a flotation type
Washed r.

---- and FLETCHER, L. A. (215)

FRUIT CLEANING METHODS AND THEIR EFFICIENCY. Wash. State
Hort. Assoc. Proc. 23: 150-162. 1927.

Warming the hydrochloric acid solution used for
washing apples distinctly increases its efficiency, so that
lower acid concentrations mny be used. For average waxy
fruit in 7Wenatchee, having not over 0.05' grain of residue
content [arsenic trioxide], 1/2 percent actual acid concen-
tration has genfierally been sufficient, and in some cases as
low as 1/4 percent, but with fruit more difficult to clean,
3/4 percent has been used successfully.* It is desirable
-to use only the minimum concentration which will do the
work. The temperature of the solution should be at least






- 59 -


80 F. and preferably 90 to f00 for fruit difficult to
clean.
.-. and FLETCHER, L. A. (216)

FBUIT CLEANING METHODS. Better Fruit 22 (8): 18. 1928.

Warming the acid bath increases its efficiency. The
temperature should be at, least 80 F., and for fruit difficult
to clean 90 to 100. 'For average waxy fruit in Wenatchee,
Wash.., having not over 0.05 grain arsenical residue per
pound, 1/2 percent actual acid concentration has been gen-
erally sufficient; with fruit more difficult to clean, 3/4 per-
cent has beenused successfully.
--- LU-TZ, J. M.,, and RYALL, A.. L. (217)

REMOVING SPRAY RESIDUE FRBM APPLES AND PEARS. U. S. Dept.
Agr. Farmers' Bull. 1687. 31 pp. 1931.

Brushing or wiping will remove only a relatively
small proportion of the residue from all of the fruit, even
if the" equipment is properly cared for.

Hydrochloric acid has been found the most satisfactory
solvent for the removal of arsenical residues from apples
and pears. Proper washing requires at least 1 gal. of commercial
acid to 100 gals. of water. For average lots of fruit with' no
particular spray-material complications, 2 to 3 gals. of commer-
cial acid to 100 gals. of water usually are enough. Use of more
than 4 gals. to 100 is not recommended.
Sodium hydroxide, when used alone in concentrations
up to 15 percent by weight, is an effective solvent for arsen-
ical residues where no basic fungicidal residues are involved,
but it makes thorough rinsing very difficult and attacks the
waxy coating of the fruit as well as the residue. It is par-
ticularly likely to injure russeted pears.

Sodium carbonate or similar milder alkalies may be used
with a fair degree of safety in concentrations of about 5 per-
cent, but their full effectiveness is generally obtained only
when the washing solution is warmed to 100 F. or above.

Raising the temperature of the acid solution gives in-
creased cleaning efficiency. The temperature should be at
least 80 to 850 F., preferably 900 to 100. Various methods
of heating the solution are discussed.

Where difficulty is experienced in washing apples be-
cause of heavy spray oil deposits or natural waxiness of the
skin, kerosene emulsion added'to the regular acid wash is
helpful. The following formula is satisfactory: 2-1/3 lbs.
kaolin, i gal. water, and 2 gals, kerosene, preferably the
odorless type.







- 60 -


Addition of 1 to 3 percent of common salt to the
hydrochloric acid wash. in many cases has resulted in more
thorough removal of the lead arsenate.residue. -The use of
certain concentrations of salt also makes it possible to wash
pears in the flotation type washer. '... ..

Proper rinsing of the fruit'-is Very important. Use
fresh' water only, for rinsing. If the same water, must;be used
continuously, .some .sixbstance such as lime may. be added to
neutralize the hydrochloric acid carried over 1by .tae fruit
and to render insoluble the arsenic remaining onthe fruit
after washing. Lime water can be made up by preparing a
stock solution of milk of lime by slaking 1 Ib. of fresh
quicklime and adding water to make it up to 1 gal. Usually
1 gal. of this solution added to 50 gals. of rinse water is
sufficient. If preferred, hydrated lime can be.added directly
at the rate ofil-l/2- to 2 Ibs. to 50 gals. of rinse water.
Broken limestone paced directly in the rinse tahk may also be
used, but is '.ess effective.

Several type% of washers are pictured and described,
and directions are given for building a paddle washer.

-.PENTZER, t. T. and FLETCHER, L. A. (218)

STUDIES 0' THE REMOVAL OF SPRAY RESIDTJES FROM APPLES AM
PEARS. Part I. Methods of cleaning apples and pears.
Bureau of Plant Indus., U. S. Dept. Agr. multigraphh),
June 28, 1928. 18 pp.

The average efficiency of removal of arsenical residue
from apples by 4 dry-cleaning methods ranged from 22 to 33
percent. In some cases, dry-cleaning methods added more
residue to the fruit than it originally bore.

Six methods employing a hydrochloric acid wash were
studied: (1) diffused spray, (2) forceful jet spray, (3)
flood wash, (4) flotation. (5) combination of overhead
U diffused spray and flotation, and (6) tank dipping in
boxes. The following conclusions were reached: (1) It is
not safe to assume that any washing method will satis-
factorily clean all fruit, regardless of its previous
treatment both as to spraying practices and method of har-
vesting. (2) Any washing method that applies the solvent
solution to the fruit by diffused spray, flood wash, flo-
tation, or a combination of these should give satisfactory
result for ordinary cloning requirements. (3) The cleaning
efficienlicy obtained with dipping methods, as commonly practiced,
was less than that obtained with washing machines that in-
cluded some form of spray or flood wash, when used under
similar conditions. (4) Where difficulty was experienced
in cleaning fruit, prolonging the exposure of the fruit to
the washing treatment longer than the common practice in






- 61 -


1927 did not result in any marked improvement. (5) The
proper washing of most apples generally requires an acid
concentration of at least 1 gallon (32 percent acid) to 100
gallons. (6) By raising the temperature of the acid solution,
increased cleaning efficiency was obtaihe-d in washing apples
from which the residue could not be otherwise satisfactorily
removed. (7) The proper adjustment of all parts of the wash-
ing equipment should not be overlooked at any time. (8) Rins-
ing of the fruit is a very important part of the process,
especially if alkaline solvents are used. (9) Reasonable dry-
ing of the fruit seems essential to facilitate packing and to
insure proper storage life to the fruit. (10) The polishing
of apples after drying is not always essential if they are
cleaned properly.

---- RYALL, A. L., and FAHEY, J. E (219)

ADDITIONAL SOLVENTS FOR INCREASING THE EFFICIETICY OF HYDRO-
CHLORIC ACID AS A CLEAITIG- SOLUTION FOR APPLES. Northwest
Fruit Growver 2 (35): 8, 18. 1930. Also in mimeographed form,
Oct. 1930.

Common salt, when added to the hydrochloric acid wash,
increased the efficiency and allowed the same efficiency to be
obtained with less acid. A stable kerosene emulsion loosens the
waxes and oils on apples and make removal of spray residue less
diffi cult.

DOLMM1, C. D. (220)

DETERGENTS AND USE IN RESIDUE REMOVAL. Wash. State Hort.
Assoc., Proc. 28th Ann. Meeting 1932: 102-117.

Hydrochloric acid does not readily clean waxy fruit or
fruit sprayed with fish oil or soap. Soda ash cleans readily,
but when the temperatures have to be raised above 1100 F.
damage results. Trisodium phosphate cleans well when the
solution is fresh. This material cannot be used at temperatures
above 1100 F. without danger of damage to the fruit. It also
has a tendency to bre'k down after short use, so that it does
not clean. Sodium silicate (50 to 101.8 lbs. BW sodium silicate
per 100 gals. water) was found effective at temperatures as high
as 128 F. without damage to the fruit. The highest number of
boxes of fruit cleaned without changing the solution has been
28,000 boxes.

ELLETT, W. B., and MILLER, M. P. (221)

THE REMOVAL OF SPRAY RESIDUE FROM APPLES. Va. Agr. Expt. Sta.
Rpt. 1919-1927, pp. 142-148. 1928.

Hydrochloric acid of 2.5 percent strength will remove
over 90 percent of the arsenic residue in 5 minutes at 70 F.






- 62 -


In strengths of 2,5 and 5 percent it removes all signs of
spray residue when either lead arsenate or bordeaux mixture plus
lead arsenate is used. The copper. is dissolved also. One per-
cent hydrochloric acid removes over 50 percent of the arsenic at
ordinary.temperatures. When higher temperatures were used, the
fruit turned dark. A 5-percent solution of sodium hydroxide
removed 80 to 85 percent of the arsenic from fruit sprayed with
lead arsenate or lead arsenate plus bordeaux. Sodium hyposulphite
was found unsatisfactory for removing spray residue. Sodium
chloride plus sodium carbonate, used at a strength of 4 percent
of each, was effective in removing the residue when the apples
were allowed to stay in the solution 10 minutes at 100 F. Hand
wiping or treatment of apples with water was found unsatisfactory.

FAHEY, J. E. (2a!)

SPECIAL PROBLEMS IN THE REMOVAL OF SPRAY RESIDIUES FROM APPLES.
Wash. State Hort. Assoc., Proc. 28th Ann. Meeting, pp. 119-
123. 1933.

The most common cause of difficult spray residue removal
is the adoption of unusual spray programs, especially those in-
cluding the excessive use of mineral oil with lead arsenate or
theli use of combination mineral oil and load arsenate sprays
late in the growing season. Another very important residue re-
moval problem is that of cleaning over-mature fruit. No matter
whether the fruit is on the tree or in storage when the waxyr
coating is formed, the result is the same. Alkali is usually
more effective than acid in removing the residue from over-
mature fruit. Unusual spray materials, such as flour and
lime, introduce another hazard in spray residue removal.
Most fruit-washing equipment now marketed is adapted to the
use of either alkali or acid for spray residue removal, but
aome of the home-made machines and older commercial models are
built to give satisfactory results with only one of these
materials,

FARLEY, A. J. (223)

S0OI EXPERIENCES WITH SPRAYING AND SPRAY RESIDUE REMOVAL
IN I07 JERSEY. N.' Y. State Hort. Soc., Proc. 78th Ann.
Meeting, pp. 87-92. 1933. Also in Mass. Fruit Growers
Assoc., Inc., Rpt. 40: 87-96. 1934.

Chemical washing removes spray residues nore effectively
than mechanical methods. Dilute hydrochloric acid in con-
centrations of 0.5 to 1,25 percent by weight is the chemical
used almost exclusively in New Jersey. It has been found that
5 minutes' contact with a dilute acid solution, immediately
after the fruit is harvested, will reduce the arsenical residues
well below the tolerance of 0.01 grain of arsenic trioxide per
pounds. Vatsol, a degumming soap, is BonetiLies added to the






- 63 -


dilute hydrochloric acid solution when the apples have an
exceptionally heavy arsenical residue or if the use of oil in
combination with lead arsenate makes it difficult or impossible
to remove the residue with loss than a 2-percent acid solution.
Spray residues should be removed immediately after harvesting, as
the residues become imbedded in the natural wax coating of
fruit if washing is delayed.

----- (224)

RE0LVZrG SPRAY RESIDUE. Va. Fruit 22: 133-140. 1934.

Most of the information in this article is based on
work done by McLcan and Weber at the Now Jersey Experiment
Sta.tion. A mixture of 5 to 5.5 gals. of 20 Be. hydro-
chloric acid m.nd 8 lbs. of Vatsol to 100 gals. of water, to
which fruit is exposecd for 1-1/2 to 2-1/2 minutes, has been
developed for roriovin2 excessive lead and arsenic residues
where oil has bccn used in combination with lead arsenate
sprays. A.ples. so sprayed, with a residue of 0,17 grain of
lead per pound, showed oily 0.009 grain per pound after
washing with this mixture, whereas acid alone only reduced
the lead to 0.056 grain per pound. Then Vatsol is used
in flood or spray.- tpe commercial '-'ar-hers, Degras, a crude
wool -r-ase product, may be used to control excessive foaming.

FISIER, D. F. (225)

iY=ER DEVELOPi,2i1TS IN THE 'ASHING OF FRUIT. Md. Agr. Soc.
Rpt. 15: 210-220. 1930.

Dry cleaning is inferior to washing. In most eastern
fruit sections it is not necessary to use hydrochloric acid
stronger than 1 or 2 percent by volume, i. e., 1 or 2 gals.
of commercial acid to 100 gals. water. The addition of 8 lbs.
of salt per 100 gals. of acid solution increases the effective-
ness of the wash about as much as doublin. the strength of the
acid. If the teF.' :erature of the acid is increased from 50
to 70 F. the solvent action is incrt--:-.sed about 15 percent.
By raising the temperature to.100 the efficiency can be increased
about 25 percent.

Kerosene emulsion added to the acid and salt solution is
useful with fruit which has been sprayed with oil and that which
has become wa-:-. A suitable emulsion consists of 1-1/3 Ibs. kaolin,
1 jal. kerosene, and one-half gal. soft water. Kerosene emulsion
should be used only with wshers which keep the solution rather
violently agitated.







(226)

i3WER lEVELOPKENTS IF T19 WASHING OF FRUIT. Md. State Hort. Soc.
Proc. 33: 64-74. 1931. Md. Agr. Soc. Ann. Rpt. 15: 210-234. 1931.

In most eastern fruit-growing sections 1 to 2 percent hydro-
chloric acid by volume is sufficiently strong for washing apples.
The speed of washing can be increased by heating the solution or by
adding salt (8 Ibs. per 100 gals.). The most unsatisfactory feature
of the fruit-washing problem is the.corrosion and deterioration of
the machinery under the influence of steam, acid, and salt.

-- (227)

CLEANIi!G HEAVILY SPRAYED FRUIT. Md. Agr. Soc. Rpt. 18: 121-131.
1933.

Any method which will satisfactorily reduce lead and fluorine
will similarly reduce arsenic residue.

Five types of washing equipment were used. The brush machine
proved the most effective. The highest efficiency was obtained in
the Pacific Northwest with the use of 1.5 percent hydrochloric acid,
plus 2 percent salt, plus 1 percent light mineral oil at a tempera-
ture of 100 F.

(228)

PROGRESS IN SPRAY RESIDUE REIIOVAL. Amer. Ponol.
Soc. Proc. 50: 25-35. 1934.

The experience of apple grovwLrs in the Pacific Northwest
can be applied directly by the eastern apple industry with one
exception. Alkaline solvents are not satisfactory for eastern
use because the fungicides used, such as liae-sulphur, produce
an alkaline residue. Reliance should be had on hydrochloric
acid washes supplemented, if necessary, by heat to soften or
melt the waxy deposits on the apple, salt to increase the
ionization of the hydrochloric acid, detergents to render physical
aid in the removal of foreign matter, increasing the time of ex-
posure to the wash, and use of brushes or rubbing devices to pro-
vide a scrubbing action. The importance of thorough rinsing must
be emphasized. Ordinarily, apples, with the exception of Mclntosh
and other tender varieties, can be w-shcd in solutions heated to
1100 F. if they are not exposed longer than 1 minute, while they
can remain in a solution at 1000 for 3 minutes w-ithout injury,
Some suggestions arc given to the fruit grower as to methods of
su.ipling apples for analysis to obtain a representative sample.
A number of charts show results of washing apples receiving various
spray schedules.

(229)

HOW TO AVOID DAMAGE TO APPLES TN THE WASHING PROCESS. Md.
Agr. Soc. Rpt. 19: 178-180. 1935.
The chief danger of chemical injury to washed fruit


- 64 -






- 65 -


arises from inadequate rinsing. The U. S. Dcp-rtnent of
Agriculture reconends that hydrochloric acid washing solutions
should be discarded and renewed after wavhi.L 1,000 to 1,200
boxes of 'apples" and 'that -6opious quantities of fresh rinse
water be applied, at, least 3 gals. per bu. if possible. If
the supply of rinsing water is limited, precautions against
arsenical burning cani be taken by using a line water rinse.

--- and P2EEVES, E. L. (230)

ARSELICAL Al.TD OThER FRUIT INJuRIES OF APPI1S RSULTIiTG
F,20:1 WASHIGOG OPERTIOCES. U. S. Dept. Agr. Tech. Bull.
245. 12 pp. 1931.

Calyx scald is primarily caused by the presence of
soluble arsenic on the apples. Its occurrence follows the
use of either hydrochloric acid or alkaline solvents as
washing naterlals. Chemical injuries to apples from hydro-
chloric acid and alkaline solvents are described. The
prevention of injuries from these sources depends on adequate
rinsin; of the fruit. IThere s,'ficient' cater is not available,
the addition of line to the rinse water is bcnoficial.

FLETCKER, S. W. (231)

OUR CO.PETITORS IN THE PACIFIC ::CROE-1WST. MLazs. Fruit
Growers Assoc., Inc., Rpt. of 34th An!. Cony. 1928, pp.
170-193.

Dry wiping machines, used in the ZTorthwest in 1927
for the removal of spray residue from apples, improved the
appearance of the apples but removed only one-third to one-
half of the spray residue. Spraying the ap:nles with 1 percent
hydrochloric acid removes the spray residue but may cause a
browning or scald, especially at the calyx end.

FORD, 0. 1., and BLC.-OLDER, C.L. (232)

SPRAY PHESIDL2 A1TD ITS PFi7OVAL FRCL.i APPLS. aInd. Agr. Expt.
Sta.. Bull. 345. 18 pp. 1931.

In the region of Iidiana, 1 percent hydrochloric acid
Sby volume is a satisfactory solvent for the relioval of
arscn .cal residue-by the dipping method. Tw.vnty to 30
seconds exposure to 1 percent acid in the flood trpe commercial
washer reduced the arsenical load below the world tolerance.
The use of 2 "nd 4 .)rccnt acid in the dipping tank was not
of sufficient added benefit as ccimarod, with 1 percent solution
to warrant its use, since it caused definite injury. The use
of calt alone or in combination with any of the strengths of
acid used wis not of material benefit. The use of wipers or
bruahos failed1 to reduce the arsenical residue. The smaller
the capples, i. e., the more apples per pound, the higher the







66 -

FREAR, 3D. E. H., and TORTHLEY, HR i. (233)

PELiOVAL OF SPRAY RESIDUES FROM APPLES. Pa. Agr. Expt.
Sta. Bull. 318. 13 pp.. illus. 1935.

The satisfactory removal of lead presents a greater
problem than that of arsenic, and certain conclusions based
on studies of the arsenic removal alone do not meet present
requirements. Hydrochloric acid, at 1 to 2 percent concentra-
tion by weight (3 to 6 gals, 20 Be. per 100 gals.) should be
used to secure maximum residue removal without injury to the
fruit. One minute exposure to the acid in a flotation machine
should be satisfactory in most cases. The necessary concentra-
tion of acid depends on the amount of lead to be removed, the
spray mixture employed, and the variety of fruit. The addition
of wetting agents oi salt to the hydrochloric acid solution has
given no consistent benefit in the removal of lead. from apples
sprayed according to Pennsylvania recormer.ntions. The use of
wetting agents may be jutstified in other States where lead
arsenate has beon combined with or followed by mineral oil sprays.
If apples are not cleaned satisfactorily with cold 2 percent
hydrochloric acid solution, it is recommended that the tempera-
turo of the bath be maintained at 100 F. Only when hydrochloric
acid at 100 F. fails to give satisfactory residue removal, may
the machinery be slowed down to give 1-1/2 to 2 minutes exposure
of the fruit to the acid solution.

GEEN, F. M (234)

EFFECT OF ACID WASH ON TIHE KEEPING QUALITIES OF APPLES.
A PRACTICAL HOME0-MlADE APPLE-WASHING' MIACHIi1. Colo. Agr.
Expt. Sta. Bull. 343. 18 pp., illus. 1928.

Neither weak hydrochloric acid solutions nor cold
sal soda solution affects the keeping quality of apples
when properly handled, but the latter is not as efficient
as the acid solution in removing the spray residue. Directions
are given for building a home-made apple-washing machine.

GRIiER, J. I. (235)

COST OF CLOANI1 G FRUIT. Better Fruit 28 (4): 16. 1934.
Hoosier Hort. 6 (6): 87-89. 1934. Wash. State Hort. Assoc.
Proc. 29: 97-99. 1934.

Washing costs for a flood type machine wore 2.76 cents
a box for acid and 2.77 cents a box for sodium silicate. In
a flotation machine the cost was 1.66 cents. The cost to one
organization of analyses and samples and of expense connected
with washing averaged 2,10 cents a box in 1932 and 3.58 cents
in 1933.






- 67 -


GROSS, C. R., and FAHEY, J. E. (236)

S0.-2O:.EF TO I CHEMICAL P'OBL3.S IT CODLIiTC- :L0T. CONTROL.
northwest Fruit Grower 2 (32-33): 7, 22. 1930.

R. H. Roblinson found that the solvent action of
h:'drochloric acid upon lead ars.:c-tc wZs considerably increased
by the aCddition of certain sulphates and. chlorides, notably sodium
chlorideo. The addition of kr3roseno emulsion (clay kaolin emulsifier)
to hydrochloric acid facilitated the removal of lead. arsenate fro-
waxy apples.

HALL, HI. H. (237)

SPPAY iESIDLM PRaiZOVAL. Mount-ainecr Grower 5(47):8-14. 1934.

Easteni-r=_,n ap-.lcs 'w7c:re satisfactorily cloned of lead
and arsenic residues by wzwhi..- with cold 0.3 percent hydrochloric
acid solution except when oil was added to the late sprays. The
use of oil interfered with residue removal e-'cn when 1.5 percent
acid was used, heated to 1000 FP. and with a wetting agent and
salt added. Sodium silicate solution has been found unsatisfactory
for cleaning eastern frewn fruit.

HALLER, U. H., 3BZAU,.:0oT, J. H., GRDSS, C. R., and HUSK, H. 7. (238)

SPPAY E.2SIDUE I-S MOVAL FRC:f APPILS. Md. Agr. Expt. Sta. Bull.
36c, pp. 121-136. 1934.

"During the growing season, effective control of the
codling moth rather than the avoidance of washing should be
given first consideration. Results in the East indicate that
ap2fles receiving five or more cover sprays of lead, arsenate
and a fungicide or lime can be readily washed to comply with
the tolerances, provided no oil is used in the late cover sprays.

"With the fruit and solutions used in these tests,
no particular advantage of any ty-c of washing machine was
apparent. Dry wiping or brushing machines wore decidedly less
effective than washing and ca an b used whln the rcsidueLs only
slightly exceed the tolerances.

"For -ap,)Ios that have been sr'.y:d with load arsenate
szid a fungicide without oil, a dilute solution of hydrochloric
acid (0.5 percent by weight) at room tcnp.' raturo should be
effective for washing the fruit. For fruit that is difficult
to clean the efficiency of the wa.rhir solution can be in-
cre".sc. by increasing the concentration of the acid to 1.5
percent by weight, by adding 1 to 2 percent of salt and 0.5
to 1 percent of a wetting agent or by heating the solution
to 100 F. or by a combination of these.

"Sodiun silicate solutions arc relatively ineffective
at rooa te.-ipcratures and, under eastern conditions, even







68 -
when heated are usually considerably less effective and
nore e:-ensive than hydrochloric acid solutions.

"Analyses of the washed fruit should be made at
intervals in order to determine whether the washing
treatment used is effective or whether the efficiency of
the washing process must be increased.

"The storage quality of apples is not impaired by
washing if properly done. Arsenical injury, which is the
most likely form of washing injury to occur, may be
avoided by thorough rinsing,"

,_ BZATiOIT, J. H., MURPRAY, C* W., and CASSIL, C. C. (239)

LEAD RESIDUES AID THEIR PXMOVAL AS Ii:FLUJENCED BY SPRAY
PROGRAJIS. Aner. Soc. Hort. Sci. Proc. 32: 179-182. 1934.

Washing with 0.5 percent hydrochloric acid at room
teiiperature reduced the lead residue below the tolerance
(o.02 grain per lb.) on lots of Jonathan and Grimes Golden
apples which had received 5 to 7 lead arsenate sprays, except
vwhen mineral oil had been used in the late cover sprays, and
1.5 percent acid at room temperature satisfactorily cleaned
the latter. With 1.5 percent acid at 100 F,, Stayman Wine-
saps and York Imperials which had received 5 and 7 sprays of
lead arsenate with fish oil or casein-lime spreader in the
second-brood cover sprays were cleaned to the tolerance. The
addition of Vatsol was necessary to clean apples which
received 7 lead arsenate sprays with mineral oil in the
second-brood sprays.

-- SMITH, E., and RYALL, A. L. (240)

SPPAY-RESIDUE REMOVAL FROM APPLES AND OTHER FRUITS. U. S.
Dept. Agr. Farmers' Bull. 1752. 25 pp. 1935.

Except for peaches, dry cleaning methods are not as
effective as washing. Solutions of hydrochloric acid and
sodium silicate have been found satisfactory for washing.
Hydrochloric acid is particularly effective for alkaline residues,
as vihen lime is added to the sprays, and is more effective
against fluorine residues than are alkaline washing materials.
It may be used in either flood or flotation typc washing
machines* The concentration of acid used ranges from 0.5
to 1.5 percent. Its effectiveness m.y be increased by increasing
the concentration, raising the temperature of the solution, or
adding fortifying materials, such as certain wetting agents or a
very light mineral oil or odorless kerosene (1 gal. to 100 gals.),
the latter only In heated solutions and flood type machines. The
addition of 1 to 3 percent of cor.ion salt has in many cases resulted
in more thorough removal of arsenical residues, but it has little
-effect 'on removal of lead and has an inhibiting effect on the
removal of fluorine residues.






- 69 -


Sodium silicate solutions (cornonly 60 to 100 lbs. to 100
gals of water at 90 to 120 F.) used in flood type machines are
particularly suitable for fr-tit that has not been sprayed with
line or other alkaline materials, which has been sprayed with an
insecticide to which oil has been added, or for fruit that has
developed considerable wax.

When thorough rinsing, careful handling of the fruit, and
frequent changing of the washing solution are observed, the
keeping quality of the fruit is not impaired. [This bulletin
is a revision of U. S. Dept. Agr. Farmers' Bull. 1687. See
To. 217].

HA. IAII, S. V. (241)

CODLII:G MOTH CONTROL. N. Y. State Agr. Expt. Sta. Bull. 627.
31 pp., illus. 1933.

With rerspcct to difficulties with spray residue, 'the
following points are noted:

1. Best results wore obtained whon fruit was cleaned
within a short tine after picki-ng..

2. :cchanical dry cleaners wero found suitable for
the removal of residues below 0.02 grain.

3. Hydrochloric acid solution (1 percent) used in
washing r.achinos successfully removed the heavier arsenical
spray deposits front all parts of the surface of the fruit.

4. When heavily sprayed fruit or fruit that has
developed considerable wax is to be cleaned in cold weather,
it nay be necessary to heat the washing solution to 80 to 100 F.

A number of materials, including barium fluosilicate,
cryolite, nanganese arsenate, calcium arsenate, nicotinQ
tannate, and nicotine-oil sprays, have been tested as
substitutes for lead arsenate. None, with the possible
e::ception of calcium arsenate, has proved the equal of lead
arsenate and furthermore, according to the latest rulings,
all but the last twro contain objectionable substances that
would involve difficulty with spray residues.

HARTIC-AIt, W. H. (242)

THE SPRAY PROBLEM. ITeb. State Hort. Soc. Ann. Rot. 60:33-41.
1931. Ieb. Agr. Bd. Ann. Rpt. 1931: 471-479.

The toxicity of arsenic and lead is briefly discussed.
Quashing with hydrochloric acid is recommended. Of 42 lots of
apples so treated, 41 met the domestic tolerance of 0.015
grain of arsenic trioxide per pound and 39 net the world tolerance
of 0.01 grain per pound.





- 70 -


HARTLAl, H. (243)

SPLAT F2SIDUE R11IOVAL IN !LATIOl: TO T-E =EPING QUALITY OF
APPLES AKVD PEARS. Better Fruit 22(12): 10-11, 28, 30, 36.
1928

No washing compound tested has proved superior to weak
solutions of hydrochloric acid. Line in the rinsing liquid
removes and neutralizes the acid quickly and completely but
it necessitates an additional spray of fresh water to prevent
a slight white residue on the fruit.

----- (244)

2Er FMIOVAL OF SPRAY MESIl7E FEO! APPLES AITD PE-:'S. PART II.
WF!2CTS OF SPRAY RESIDUEZ 1EIOVA 15 ON TH3 I2PIUTG QUALITY OF
APPLS A1TD PAi.RS. Orog. Agr. 3xpt. Sta. Bull. 234, pp. 23-36,
illus. 1928.

Cleaning by mechanical means is apt to cause bruising
and stem punctures in poars and to reoavc the bloom froir apples,
causing excessive weight loss during storage. Washing, when
properly done, results in no serious injury to the fruit but
rather increases its attractiveness. If the fruit is not
thoroughly rinsed, injury from acid or soluble arsenic may
occur. Deep submersion of open-cored fruit results in in-
jury due to penetration of the core. Calyx injury may be
caused by acid left by improper rinsing or by soluble arsenic
which has been allowed to accumulate to too great an extent in
the solution. Too prolonged exposure to the acid nay result
in burning the fruit.

----- (245)

SPRAY F2SIDUE EMIOVAL IN 1928. Better Fruit 23 (9): 13-14. 1929.

Failure to clean below 0.01 grain of arsenious oxide
per pound has usually been due to one of the following factors:
(1) E::cessive wax development, (2) coatings of dust and other
foreign matter, (3) improper use of oil sprays. (4) excessive
applications of arsenate of lead, (5) insufficient strength
of washing solution, and (6) improper handling of washing
equipment. The use of hydrated line along with the sprays
apparently facilitates sor.-cuhat the removal of arscnicals by
the acid process. Heating the acid solutions to 95 to 100 F.
increases the efficiency of cleaning.

------(246)

TIM REEiOVAL OF SPRAY RESIDUE W THE WASHIiTG METHOD. Ill.
State Hort. Soc. Trans. 63: 179-183. 1930. Hoosier Hort.
12: 158-162. 1930.


The process of washing apples with hydrochloric acid






- 71 -


L dCLcscribcd. A .va.nh coalition con.ai.int; 5 to 7 ets, of
ccnce,2i.tlaud aci tc 100 -a,.s. uf .,at r ic a.f-"'cicrnt urcr
ordinary cirmunita .cez. Late In the season it is Loietir.;e:
r.eccssr-ry to increase the concentration to 10 or 12 qts. per
100 Zals. Diffuse pray, flood warh, or flotation. tpes of
washers are s :cessfuil, Deep s'brcersion ty1,es arc unsatis-
Iet cry. Thirty to 40 seco-ics trestanefrt 1is usually 1 :ficient
in the first t.v t:-poes of r-cnhine, whils 4 tc 5 nirutes are
often req'.ircod In the flotatic-, tame. Rinsinrg should be
thorouIgh. A'-:;rated line 4n the riwse water ina- b- of
value, especially u.hon abnmanrt ri-.se water is rot available.
thorough dryirng is not necossary Wa hi::g -hould be don.e soon alft-c-
picking.

-- -- CHILDS, L., Rad RI,:-3i, R. (47)

TIM OCCY;JdTC T 7D PSI3V3HK'!- F O' C^iLY: IlJ= r--T IT PPL S RIO
%-.E HO0Di) 1V1 VALLEY. Orcg.R A-. LxVE. CtY. 0-]2. 2,1,
24 ?., illus, J1929.

Calyx injury attrLbuaebl> uo vAe vad.hi. 0rocrss is &uo
primarily to arsenic rendcru. rl- b'0 7 -r co: poLrd
or by" prolonged epcsurc to r0 i.-.t'-r'c. .c o t cly; L.
attributed in pasb yao-rs to :n-1.": *, s-; ppar t, havy occurred
in the field prior to thl- wrshig tr .t-,ent. "a-i comonds,
such as hydrochl.oric a.ciC'- odin cabo-.,o-t- 7odiuv hydroxide,
and trisodiur.- nLosphate, when left in the calyces b: tnm-hm-
solvcs, dl produce physiclogical injury, out r-ot of th C cimn
type, andi it seldom results in decay. Arsenicals r--i.,..-- ii
the calyces eapear to be a rore conimn cause of cal-.x injury in
washed a.-les. than arsenic accxumulating with repeated :se of
the solution. Eydrated lime used in the rinse bath .s
effective in re(ducin calyx injury 7hlein the acid process is
used. Then pr:-'-rly done, washi-" tends to reduce cal--
injury under Hood River cc.ditions.

_-_.- d .RC'5::-SO1, L. E ( 48)

C--,, C- RID OF SPRAY ESir'. r..rr.. Jour, I (D): 2-, S0. 13-7.

A report of work '-one by the Oregon Sxper'.eint Station
on the rerovol of spr-y residue f-or ai a. ear. Wshi
with 60,25 to 2 -porcent hydrochloric acid is rzcor'onded.

---- and F:L)rST, 2. :1. (24)

T7-TS SHJO O-'7 TO P-Z,3VE SPRAY LIDj. Better Suit 21 (7): 5-3,
16, 1927.
: r:.ss ti r 'ac 0 2 L.4. ie
Hiechanical cleaning of fr.ij t wc-s fni1 ..'.. ti facto.y. The
follo'.'inL., materials were tested !r w-ashps for t ri.ioval of
spra:r residue; Inorganic ac d--n-d rroc .oc, nitric, sulphuCic,
sulphur uo, r hosphcric, toric; bar es-.-sodi" LydI-oxide, potassijn










hydroxide, sodium ca.roonate, sodium bica-.bon.at., calcium
hydroxide, amn.onium hylroxide, soda lime; salts-sodium chloride,
potassiumn sodium thiosul'-,ate, amuoniur. chloride, sodium borate,
copper sulphate, calcium su.lphate, sodium chromate, sodium acetate,
sodium nitrate, celciam acid phosphate, calcium chloride; ore:- ic
acids--malic, citric, tartaric, acetic, oxalic, tamnnic, carbonic;
miscellaneous--cane s2ear, glucose, alcohol, sodium stearate,
sodium oleate, misclble oils, potassium benzenesulphonate. Of
these, hydrochloric acid gave the best results. Used at con-
centrations varying between 0.25 and 2 percent, it was very
effective in the rzrrovw'l of spray residae and proved non-
injurious to the fruit when properly used. In addition, it
possesses rman;- advantages: (1) It is comparativelr cheap and
can be obtained in large quantities. (2) It is effective at
low temperatures. (3) It is a ncn-oxidizing compound and, there-
fore, it not apt to cause, discoloration, esp cially in injured
tissue. (4) It is volatile and disa.ope.rs of its own accord
where rinsing naJs not c-aun thorouhlly done. (5) It is easily
washed from the fruit 4ft 4.r treatment. (6) It is not dis-
agreeable to iork with. (7) It rmoies from the fruit not only
the arsen'cals but alo lad., co-er, and other foisT of residue.
(8) It does practically no d'-x.g, to the wax or protective
covering, and luaves tbh frait in a clean, attractive con-
dition. A neutralizing ba.th is unnecoss:.ry unless efficient
rinsing cannot be done.

nitric acid is effici-nt i:- the removal of residue and
wvhen properly used does not injure the fruit. Ho'./cvsr, it is
more e,:pensive, is an oxidizing; .gent, .rd is less volatile
thnn hydrochloric acid. Acetic acid is ineffici.; .t except at
high concentrations. Sulphuric acid removes the residue but
in some cases :nm- d2-' e the fruit.

Although bases in gtner:A.l tend to remove spray residue,
sodium hydroxide (caustic soda) is the only basic compound
discovered in these studies which successfully removes
lead .rsanate under all conditions. It is inferior to hydro-
chloric acid in several ways.

Th. efficiency or rate at which solvents remove spr"y
residue is influenced by several factors, emoein; which are
(1) the concentration. of the b-.th, (2) the temperature of
the bath, and (3) the ler.a:h of time that the frait is sub-
jected to tretm.int. These factors have about an equal effect.
Agitation of the solution during treatment is ver-' important.
The use of oil or spr; 2ders in lead a.rsnr2.te sprays retards
removal of the residue Apples are more readily clccned at
picking time than after wax has developed.

-. an-d ROBIinSO.:, R. H. (250)

OBSERVATIONS ON SPRAY REkOVAL. Better iruit 22 (8): 24, 57.
1928.











i.'echanceai cleaning methods are uatisfcory. Vhi
with ?y,:.rochlcric acid hfis u'ualll beern effective en&d a- I1e. to the
attractiverj.es of the product. 7-.:pio-g mcninen eEpioyng the
flotation, splash, spray, or sluicing systems h-,ve been uetis-
factor-,- ill most cases. ordeaax aix ,re used ii. combinaftion 7ith
late sprays meterially facilitates cleaning by th> h-dro cnloric
acid. m-nethod. Lin; (calcium carbonL.te) will probably ce1omplish
the sam- resrlLts. IorlialudeY-- 3. used i- h' acid b th terl s to
keep it free from viable decay spores. Plenty of frsn atr
should be busad in 'd.i nr. r.

- an- ~d. r^T:Z., S. j,.i. 1

THE R IIV07. Or SFr2 RC: x. RE SIIX.PLES Al PAT III.
DISI'l^CALTT. Ore-. ..-r. E:;pt. Bu.. llu.i. 2ZI1, 69 -36.
1928.

P.bul. obtined. o- co-c rci*! lots of .pples show 0.9
percent dec:_- from .11 cause i. t-e fr.Lt 'x.sied iith 23ydro-
chloric acid LlonJ and 3.L r'.rcrnt 'U: in thi f-uit -"a.shedO
with >,d.'occ.ior. racil ;. ormil2iuhyu.e,



SPRAL RZSI2Ji PAi0"AL ZY Sa.A:AL .JJJJ IS i_SV!LY
r -- -- ... -' -<' -i.
tzz.~, 'o-lbook of `-06. 1 :09; 5o5L. 1<-9;

Dry- wiping is inefficient .for recnovlJ. oL,' 3'.y si
from apples. Nu.:nerois ,i f. solutionS _'re ~,ri, d. i..nral
acids an d alklies dissolve thv ......... ue r id -e rn1 of c.esof
hy,-irochloric acid end sodiumn cr'.rbon_.,, or LixCu...s of odium
carbo-xate aid sodium hydroxide, are tsed most, th. '-cJ i beirg
used mor; thirn the alkalies.

:JL{;AhQ, *.1. P. (253)

R.:'I'OVALU C!, .D TS.IA J^.. SPEAY3fD O-,jIT, Colo. .,-r. Expt.
Sta. Press Ball. 63. 4 pp. 1925.

,;.:.lhi. of :pplos in a solution of 4 !.C. of sod. ash
and 4 lbs. of tabIe salt in 100 -aIs. of -jator ct 1000 .
for 10 minutes uith ntle stirring, foilo:ed by rising,
will remove lead arsenate rcsiduo.

HEALD, D. (254)

A2.SEN!ICAL ?-z-b2DL 0 A- PPLS A P-. sh. r. t St.
Bull. 222 (Ann. Rpt. 37): 33-40. 1937.

Dry wipin; does not brirn the arsenrcal. r sidue down
to 0.01 grain of arsenious oxide eor pound of frijt V:.\'_'t
in earl- verieties or after light s-.' schedules. C'Lr.icrl








-.74-


washes have proved r,'ore effective a-rd have been pat into
commercial use. Study has been irmade of different types of
wet process machines employing both alkaline and acid baths.

-.---. ELL-iR, J. R., and CV'-.LEY, F. L. (255)

SPRAY xE'SIZU REM0V; L Fh01. WJS'iJGOi AFPLrS A1JD PEA-.S DTjrITG
1927 SEASO.. Better Fruit 22 (12); 15-17, 32. 1928.

A summary of work presented in Wash. .r. Expt. S~a.
Bull. 226(257).

i--- IELLER, J. R., OVERLEY, P. L. and DAA, H. J. (256)

ARSENIC L SPP. Y RESIDUE ijD ITS Ri.iOVJAL YCTm APPI.S. Wash.
Agr. Expt. Sta. Bull. 213. 56 pp., illus. 1927.

Dry wiping of appl.*s to remove spray reside is not
generally effective. Zh reimoval of arsenictl residaue from
apples by spring the e^ics on the trzus with w,'ter or with
water plus some solvent -,s not b3en successful. A'rsenical
residue has not been removed to comply with the int'r-nti-oonal
tolerance by machine treatments in which a driving siraj of
water has been used, even though supplemented by a brush
wiper. Of the numerous solvents tested in hand w'ping, socking,
or nrachiiu processes for the removal of arsenical -:,id e,
hydrochloric acid and nitric acid are the most po'tunt at
ordinary temperatures, the former being better suited to
commercial use, being cheaper, less corrosive, and causing less
injury to the fruit. (Vinegar, acetic and sulphurous acids,
ammonia wviater, sodium hydroxide, borax, alcohol, and acetone
were also tested.) Soaking apples for 10 minutes in 1 -ercent
hydrochloric acid by volume folloi'ed by rinsing in w'ter is
generally effective in reducing the arsenic to the international
tolerance but it is too time-consur.ing and cxptnsive. Hand brushing
in 1 percent acid indicated that the time required for removw.l of the
residue could be reduced to about 30 seconds at 65 to 75 F. threee L
types of machine devices for carrying out this process, usi.ij 1 or 2 perv
cent hydrochloric acid, gave promising results; (a) cylindrical rotating
brushes in a vat of the acid solution, (b) a spray of acid from en overv-
h-:.rging perfor-.ted pipe forced on to the apples as they arc carried for-
ward over spire1 roller conveyors, and (c) a similar device -.,ith thd spre
from clipper nozzles. The pressure spray system is better than a wet
brush process. The use of cn oil spray appears to mika the removal of
the arsenical residue by the acid process .;ioro difficult.

----.-1 ELL2R, J. R., 0V-:-L-lY, F. L., RU.JEHLi, G. D., and LUCE, W. A. (257)

ARSEITICAL SPRAY R-SiDUE K:D ITS PRiO0VAL FROi., APPLES A1,D P:tRS. iWrsh.
Agr. xcpt. St.. Bull. 226. 100 pp., illus. 1928.

Averaging the results obtained with Jonathen apples, 7 wet ,nd
3 dry cleaning processes h.ad the following order of dae-rc,2sing eff.c-







- 75 -


tiveiess: jet spray, fan spray, flotation and spray, flood washi, flo-
t-tion and din, box din, flotation spray (ealkeli), vibratiring
bristle brushes, rotating bristle brushes, and, rotating hemp brushes.
'-e rsenical lo-,ds on'unclemnel lots of Il var eties var-ied from 0.015
to 0.075 grai-, ritlt an avera.te of 0.0,12 grarn of arsenical trio de -ner
noJundL of fruit. The aiicunt remaininr- aift.r vet cloning ranged from
'..0079 to 0.015 with an average of 0.011, and after d-:y clearing
f-ro- 0,021 to 0.027 with ?n acrge,- of 0.024 grina per pound.
or the effic-ent cleaning of w'.-,", varieties of apcnles, such
.6 ViTnenap and Arkansas Back:, -usig- fnlike spray of dilute
h-idrochloric acid, the temperature of -he solution ma-orcnt-y
-.Louuld be close to i00 F. In a jet s-pry n:,ci]i e ccn-
idcrable loss in cleni2in efficiency reputu fr,:i directing
t,.C spray uo against the cover of the m1aci r "- of
'Jiructi.- I-c'inst tnrc fruit. On the avetrag, fr.it h'.du-ii
cold storab-e for four months iforc clai'-. wa 't cI 'nec
so 7C1 as portions of the o-; lots cli.o in t'. t In WI ,-;y
--t harvest time. Small apples carried larger 7oe2,C of arsenic.1
residue pcr ,.cund of fruit than large both bicr. ai.d
after n". :i. The use of special '"apl sray sar lied,
six days before harvest did .ot re.ov. any of the ersenical
r side nor make it any nore easily rutroved lT' dry or wet
cloning. A-senical and acid "'uri.n-g of the core cells :.r
occur in fruits with an or.c. calyx canal if a suc-". rsicn process
of cloeniu:-. is used. The i.-i-ortance of keeping down the sooro
content of tne treat ing and :rinsing b.thc is euphasized. 'hc
acid tanks and machines nay be sterilized over night by the
use of fo:T..:'- hyde solution, 1 part to 8C00 of v.'a .-r for 10
to 12 hours being ecno'ugh to fr.e the machine completely of
blue nold and other f.i.. Th- use of 1:400 fornnld4rhyde in
the relaur run would be equivalent to changinJ tl-e ; oli-tiors
t.vory 5 hours. Pack-i-.ng the vashod an-plos 'l.il w-t d little,
if any effect in incrcas :'.-' th inci ,n cc of dc"," In cold
-torago, while in comnron storage there .7as a slight increase
1 0, cay from wi t packing.

HERB`2, J.W. W, 5)

T?2 AISE":A3Z OF L.AD SIV'-ATIO. Idaho- State leort. Assoc.
Proc. 32: 53-59. 1-27.

A brief history of the situation. 7ipir-.g is irefficioi.t
.-i re-iovlng spray residue froi.i fruit. Tiiorc 'ar two ooivwnts
[not naneod] satisfactory for wasning. Hydrociloric acid
solutions have beer uced succes.-if-:ly.

HEDRICIK, U. p. (259)

FIFTI7TH Ai:TUAL E::TORT, Y. Y. Agr. Expt. Sta, A-.'. h t. 50: 122.
1931.

Washing machines sing dilute hydrochloric acid as a
washing solution were found to bo vzry cfficiei.t in rencving





- 76 -


c.rscnicnl residues front fruit. Cormercial dry clcnncrs were
less effective.

B A0:, -A. M. (260)

124 IOVAL OF RLSILUAL.POIS2S FOV PFITS AND VWGETLLS. U. S.
P:.tent 1,967,176. Issued July 17, 1934; Lapolied for .I:-, 14,
1927; assign*.d to U. S. Govom.ernont and People of tlhe United
States.

Residues of poiso-s .-i:cl ->s ar.Fcnical spra: s arc removcd
by use of a dilute solution of a stror.g acid such as a 1
percent solution of sulphuric acid or h,-ydrochloric acid,
Alhali solutions also nay bo used.

-----O- (261)

PPDCESS FOR TiH, .LOF. L OF E2SIDUAIL PO:SCL'S FRc.i FRUITS AID
VEGEn.'rLZS. U. S. patcnt 1,975,Z3.; ssucd Oct. 2, 1934;
appie, for ril 19, lc.-; ..ss to the Goverr-mnent
and people of the United States.

Residual poisons suc. as those fro-i the use of arsenical
sprays are remove from fruits or vCietables such as grapes,
apples, or pears by vl'e use of a dilute solution of an alkali
such as a 1 percent solution of arm onia or soiun h "ydroxide.
Other alkalies such as sodium carLonate or sodium bicarbonate
or mixtures of alkalies nay be used.

H-ERA-CI, R. S. (232)

REPO0M CJ SC-T Aff -lFE.-SnSl. EE. Iowa Yearbook of Agr. 1927.
616 pp. 1928. [pp. 242-2453

S. L. 2cdfcrn reconr.uc.s washing a-.plcs in 0.3,r5
percent hy rochloric acid for 5 to 10 Tiinutes to renrove
arsenic sp.ay residues. Tl-is solution is trade by nixing
1 l. of commercial a.cid vi 100 jals. of water. When this
is sprayed on t1he. fruit 'unrer 8 to 10 lbs. pressure for 30
seconds the aresenic is effectively rer.oved.

hOLLkTD, C. S. (263)

SPi Y :CSi:lj R-EI:OV1L. Ohio State Hort. Soc. Proc.
64: 44-53. 1931.

7e.j :- of fruit vril' Lyd.rochloric acid, 1 gal. of
:o-' icrcial acid to 99 gals. of rather, is roe':l,.cc.dn fcr the
removal of arsenical residue.

(364)

-2 SPPJY IlSIDUE SITUTIOI .S IT EXISTS IN OHIO. Aner.
Soc. Hort. Sci. Proc. 1930: 543-545. 1131.


Of 73 samples of apple] s .-xxinrd, only 1 Lad over






- 77 -


0.015 grain of arsenic trioxide per pound. The use of
:>crated line with line-sulfur and lead ars.nate, as recommended
in the O'io spray schedule for apples, tends to reduce the
residue. T7iping rmonovcd 30 percent of the arsenical residue
on Ohio apples. Hy-dr6cichloric acid at both 1 and 2 percent by
volumc took off 80 percent of the residue on Wealthy apples
which had an average of 0.025 grains cf arsenical residue.

---- (265)

::.;OVAL OF SPRAY ICSIDUE FROM OHIO GRO'..'! APFL2S, Ohio Agr.
Ex-pt. Sta. Bino. Bull. 151; 123-129. 1931.

Dry cleaning of fruit with cm-crcial "7:ping macLines
will remove 30 percent of the original arsenical residue
and may be employed wh.er. the residue is between 0.01 and 0.015
grain per pound. The uso of hydrochloric acid as a solvent
for the residue was for-nd very effective, re-moving 80 per-
cent of tlc ori-inal rcsiduc. Tests to determine the optimum
strenL"th of acid showed that 1 percent by volume of commercial
acid for 3 minutes was the wcakost effective solution. The
tycpe of washer to be used dpends on the volume of fruit to
be he'._.led. Hand dipping is to be considered only if nothing
else is available. For less than 6,000 bushels, a home-made
flotation wlsher or a commercial machine without the dryer
is recommended. Commercial washing machines can be used to
advantage where over 5,000 bushels are handled.

HORSFALL, J. L., and J4L14E, D. W., Jr. (266)

A DEFOALINiG MATERIAL FOR USE IN APPLE "AShIi'G I.-ACIHIIIS.
Jour. Econ. Ent. 27: 259-261. 1934.

De Gras (wool grease) thinned with petroleum naphtha may
be used to control excess foaming when Vatsol is used with
certain wazhing- conipounds in commercial apple washing machines
where agitation is present.
HOUGH, Y. S., and GROVES, A. B. (267)

PPOBLMEiS AI.D EXPERIEiNCES IN 1.OVIiG SP' A RESIDUE FROiC, THE
1930 APPLE CROP. i.d. Agr. Soc. Rpt. 15: 220-234. 1930.

Wiping machines will not consistently rencmove more
than 30 percent of the arsenic from apples.

One minute in a bath containing 1 gal, of hydro-
chloric acid to 100 gals. water removed 66 to 73 percent
of the arsenical residue. lashing by dipping was efficient
but is not recommended. Paddle 7rwshers iave considerable
mechanical trouble. Commercial washing machines of both
the jet spray and the flood types were satisfactory.






- 78 -


Increasing the acid concentration from D.1 to 3.25
percent (from 1/3 gal. to 10 gals. per 100 gals.) gradually
increased the removal. According to best infornat*on the
addition of acid beyond 12 gals. in 100 gals. is nit justified
and some growers do not think it safe to use more than 4
gals. The limiting factor is not the strength of aql
solution but the amount of fresh rinse water used.

----- and GROVES, A. B. (268)

PPI231.IS ATD ::N2RIzI1CIS IN _iIVIJ' SPEAY LSID"E FROi: TFK
1930 APPLE CROP. yd. State Hort. Soc. Proc. 33: 74-82. 1931.

Wiping machines are not dependable to re'aove more than
30 percent of the residue on apples. One minute irlersion in
a bath of dilute hy-rochloric acid, 1 ,-1rl. to 100 gzls., removed
66 to 75 percent of th, ar3seical resiluco. Dipping, paddle
washers, aid jet ,--'iy lnd flood ty-err conrier,'ial machines
:re uod srti '.ctrily df' ,r the first w ck in October,
whcn the to. ,at, xro of t', witer f.ll to 62-72 F., 2 gals.
of acid :r C -s,, 0 ol uAition wero vssd. The addition
of 8 ibse, of salt to 1)0 jal3. of sotliion in a co;.Lercial
viash-r dded somewh ,t in rP s1 iua remnov2l feroa apples in cold
steor .... eatit" tie solatior to 100-1l0 F. also aided.
In laor.,toiy ex1Dcrents *stj the dipping or flotation
method, the addition of 1 percent of salt to the acid did
not a pear of practical value.

---- HUET, R. H., -LL:'YT, v. B., _ZART, J. R., and (269)
GR1C-:S, 1. 3.

F-:DV-AL OF i HSI F:I".; APPLES. Va. Asr. Expt. Sta.
Bull. ,::. 16 pp. 1.l.

Three spray-s of 3 1'-s. of lead arsenate in 100 ,,,als. of
wJater aplied in Ia.y and Jl.ne did not necessitate removal of
s-raa- reisidue froia tie frjit at harvest time in September.
An arse-ic'-l spray applied during the first half of July may
leave excessive residue on the fruit if followed by dry
....ther for the remainder of the season.- An arsenical
sor : applied late in Jul. left an excessive residue for
the remainder of the season, although rainfall greatly
exceeded normal for August and Septembcr, A,:' roximately
ha1lf the arsenical residue is distributed on the side of
the apple, the rest being in the calyx and stem ends.
'iping or brushing the fruit removed a,-proximately one-
third of the arsenical residue, on the av 'rajc. 7"ashing
fruit in dilute hydrochloric acid consistently removed ex-
ceosive a:r', r' cal residuecs. One gallon of commercial acid
(20 Be.) was usually used in 100 gals. of wash solution.
Then the day temperature dropped below 600 F. in October
anc1 whcre the residue was considerably above the average,
thn, strength of the solution was often incr: Lsed to 2 gals.






- 79 -


of the -cid in 100 gals. of v'-sh solution. Far each bushel
of fruit, 1 gal. of fresh rinse water, doli-vercd through spray
nozzles, removed traces of acid from the fruit. The towel
method of wiping and drying washed fruit was more satisfactory
than air drying, because the former removed leafhopper :peckin.j
and smears from fungicides or dust. Washed fruit kcpt as well
as unwashed fruit when packed and stored in barrels or baskets.

IS LY, D. (270)

T-. SPRAY PESIr-E POBLZii I- ARKAITSAS. Ark. State Hort. Soc.
Proc. Dec. 6-7, 1928, pp. 14-24.

It has been generally agreed by all investigators that
arsenical residue can be most satisfactorily removed by wash-
ing fruit in dilute hydrochloric acid. The dosage usually
recommended is 1 percent by volume. Wiping is not as efficient.
Abundant rinse water, at least 3 gals. of fresh water for each
box of frait, should be used. If this asiount of water is not
available, the use of lime in the rinse water (2 lbs. of milk
of lirm. to 100 gals, of water) is recommended.

JARDIiU, J. .. (271)

DiULCTORI'S BPOPlIAL 3?-PE, 1926-1928. Oreg. A-;r. Exvt.
Sta., Director's Bienr.. Ppt., 192-i?1228. 133 pp. 1928.

The most outstanding accomplishment of the bi-
ennium has been the development of a fairly satisfactory
practical method for the removal of spraj residuc fran
fruit, wV-s,,`'hi- with water solutions of hydrochloric acid.

------- (272)

Di_-.CTOR'S BEI_:AL }EP0or', 1928-1930. Oreg. Agr. Expt.
Sta., Director's 3ienn. R-pt., 1928-1930. 143 pp. 1S30.

COlyx injury of '-olos by arsenic can be prevented
by- the following precautions: (1) Keep the froit dry after
.cirn.; (2) do not delay harvesting oocrations; (3) use
line or bordeaux mixture in lato spr:ys; (4) wash as soon
as possible; (5) use line in the rinse bath.

JEli.I S, B. A. (273)

FRUIT UASPHRS AI'D SPP-AY 1SIDU REI0iOVAL. Agr. Erii.. 15:
244-245, 248. 1934.

Standard hydrochloric acid may be used in washing
fruit that lh's bocrn spr:." cd with lead arsenate. The temperature
affects the efficiency of nearly all solutions. Apples c n
sa'..rd a temperature of 100 F. safely. In gencrl, incrc:..si!-.g-
the strength of acid increases the efficiency; however, there




- 80 -


is a nalrked differcrce between 1 percent and 0.5 percent.
The s:,fe limit is 1.5 percent, but there is little
difference between a 1.5 percent and a 2 percent solution.
Apples mnny remain in these solutions 5 minutes as a maximum.
Apples spread with oil sprays, apples with a very heavy
residue, or apples from storage which have become waxy
rcoquire a wetting agent in the hydrochloric acid bath.

Sodium silicate and trisodium phosphate were found
not to reduce lead sufficiently and. 'aso ruqure a temperature
of at least 800 F. "

J01S, F. S. (274)

-'0VIiTG iE PRESIUTE FROMi APPLES A1TD PEARS, Amer. Fruit
Grower 48 (7): 3-4,20; 48 (8): 8-9. 1928.

The first article outlines the introduction of acid
washing methods and, &.escribes three t;pcs of washing machines.
The second discusses the cear.i: solutions. Hydrochloric
acid is the nost practical. Five-tenths percent acid has
usually been sufficient, d-though in particularly stubborn
cases up to 1.5 percent was used. Tl-. use of ninoral oil
in lead arsenate sprays nakcs cleaning more difficult, as does
tne dcvcloprent of wax in storage.

JOLTS, V.' C. (275)

Ti1 ARSZ.IC SPRAY PISIDU3 SITUATION IN VIRGINIA IN 1930,
A1:D 7-:L PART PLAYED BY DIVISI01I OF CiLI.:STRY IH lELIUVIiYG
ThE SITU'TIOI-, IN CO-OP_,TIO1,T '.:ITH OTK2R AGBTCIES. Va.
Dc-t. Agr. and Innigration Bull. 279: 28-30. 1931.

Thi, work of `7. S. Hough on wash-in, of apples with
hc1-rochloric acid solutions is quoted.

Of 5,159 sanplos of Virginia apples "h1ich wire c an.ined,
534, or 10.15 percent, carried arsenic in excess of the
foreign tolerance (0.01 grain arsenious oxide pur pound) and
181, or 3.31 percent, exc-crded the doncstic tolerance
(0.015 gra'in per pound).

K., 2. (276)

=:0VI:G SPF.,J ESIDUD. Ancer. Agr. 130 (1): 6. 1933.

Describes experiences of a conncercial packer in wash-
ing apples to remove arsenical residue. aig with 1 to
3 percent hydrochloric acid is rcco..n.ndod.

KDf,:.J. (277)

USIHIG P.C0iAi2NDATTi0TS FOR ILLIi-0IS. Ill. State :Iort. Soc.
Trans. 67: 269-275. 1934.
".h- use of a. flotation washing .achinco is reco-Inondod.







- 81 -


Flood and spray type machines will not give satisfactory
rcoval of high residue miunless underbriushl-s or a prodip tank
are used. Hydrochloric acid has boon ur.,rior to sodium
silicate solutions. The solutions reco-:'eandced for the various
types of machines are: Flotation or hand dipping--1.25 to
1.5 crcent actual acid at about 100 F., with about 1
-npercent of a wetting agent, for 2 1/2 minutes. Flood and
spray type nachines--1.25 to 1.5 percent actual acid at 100
to 1100 F. with wetting afe:nt to give a good foan, tine as
reconmended by the manufacturer, Underbrush flood machines--
1.25 to 1.5 percent actual acid, heated to 100 to 1100 F.
when residue is high or fruit greasy, for 30 seconds, no
vetting agent necessary, a predip in a good wetting agent
being used if residue and wax are both high. Rinsing should
always be thorough.

KXrIDALL, J. C. (278)

AGRICULTURAL RESEARCH IN iMW HALiPSHIBE. Y. H. Agr. Expt.
Sta. Bull. 270. 27 pp. 1933.

Only a few suamr] es of Mew Hampshibre apples carried
arsenical residue -*ven slightly in excess of the tolerance
in 1932 although it was an unusually dry season, Tiping
appeared effective in reducing the spray residue but it is
not recormLended for apples carrying arsenic greatly in
excess of the tolerance.

----- (279)

AGRICULTURAL ESA?.CH IN U.D HAMPSHIF. r. xpt.
... C SEI-H-y7. F. --r. Expt.
Ste. Bull. 280: 31. 1934.

Running fruit containing excessive lead arsenate residue
through a machine with brushes and two sets of polishing cloths
did not reduce the residue sufficiently. When run through
a -oaddle type washcr containing 2 parts by volume of hydro-
chloric acid to 100 parts of water at 70 F., both lead and
arsenic were removed to a small fraction of the tolerance.

KN2IGHT, H. G. (280)

MEPOPT OF TM3 CHIEF OF THE BUr2AU OF CIHi3'ISTYY AND SOILS.
U. S. Dept. Agr. 30 pp. 1-28.

As a result of excessive arsenic residue on apples
shipped to England and other countries, the vihole apple
export industry was jeopardized. A cooperative investigation
will be undertaken by the Bureau of Entomology, Bureau of
Plant Industry, and Bureau of Chemistry and Soils to devise
effective means for removing arsenical spray residue without
injuring the apples. affective substitutes for lead arsenate
will also be sought.






- 82 -


(2 81)

PEPORT OF THE CHIEF OF THB BUREAUT OF CHELIISTEf AND SOILS.
36 pp. 1929.

It has been found that the addition of certain salts,
such as sodium chloride ar.d sodium sulphate, greatly enhances
the solvent action of hLydrochloric acid for lead arsenate.

--- (282)

PORT OF THE CHIEF OF THE BUMAU OF O2MISTlY AND SOILS.
67 pp. 1930.

A portion of the hydrochloric acid in the usual
acid wash may be advantageously substituted by sodium
chloride, providing a cheaper wash and one less injurious
to the fruit and machinery .

(283)

REPORT OF THE CHIEF OF TM. BUrIEAU OF CBEiSTYI JA) SOILS.
78 pp. 1931.

The quantity of arsenic left on apples by various
spray treatments and the efficacy of numerous washing
solutions in removing it under different conditions were
determined. A study of the effect of sprinkler irrigation
showed that high sprinklers playing on the foliage tend to
reduce the arsenic residue. Several hundred analyses for
arsenic on tobacco were made and the residue per leaf found
to range from 0.12 to 3.52 mg. of arsenic.

(284)

-TORT OF THE CHIEF OF THE BUREAU OF CHEMIST.7 ANTD SOILS, 1933.
51 pp. 1933.

B3ccase of the establishment of a legal tolerance for
load in foods, the solubility of lead arsrnate in x"cny
different solutions of acids, alkalies, and salts has
booen dctcrmined to aid in selecting solutions which arc
capable of removing load from apples. A new procedure was
devolopod for the dctcraination of lead in residues.
Washing tests were made on various lots of fruit sprayed 'vith
.... various combinations of lead arsenate, nineral oil, fish oil,
and cryolite. The fruit had been stored at 50 and 100 F.
and washed in a flood or brush t'pe washer with hydrochloric
acid, soda ash, or sodium silicate. No difference in the
efficacy of the three solutions in removing arsenic could be
detected with the fruit that had received cryolite and fish
oil in the two final sprays. When mineral oil had been
used throughout the season or in the final sprays, best





- 83 -


rnr(Lovl wo' obtained c4wi' soda ash. :-SC^ic in -pl'i:i
!ad. ar's^enate was removed (o. .lly l l ,A ;itl rixy cf th
thre, ,7:qshos. L gonero.l, ngnit heo1 in col' stor,)c '*o,
more cc,.,:=] ceoared thar .that he-dr. in 'omnion stora;c.

------- (2S5)

TCPOTR T? :0:- CE:OF OT t-E BE-JAU OF 3ZIST" M.D S.O.S,
19'A. 54 n 9

The mo;t :,timfacto13, -roccd'aroex for .shr- nd aoyo fo
were foluid to be hydrochloric acie. ,lus mireral oil in a
br'ush-floo, machine anJ. sodium silicate followed by hydrc-
chloric acid in a double process machine. An in'.vestiation
of the solubiity of cryol.te in chemical solutions establ ishe d
that elhuinum E.alts, ferric salto, .ord boric acir in 'he preaence
of ,yrdrochl'oric acid. improve the solvbiJiy, ,'hereaf. sodium
chloride and othn r sodiumr saltv .eprcsrc tns F.,rili1ty.,

.LAiC.:S, I. F., rj^S, H. P., a jT IFRPEY, 23. (236)

:.'Tf.0D OF CL" ..._ C- A!,D FEi3- ARBlY O:' SF0... .I-D ;...;--C_1. FE:IT
AJ: H1 ARVESTII G-, JU. S, ..atent .,7:,,31; iss-red October 2,
19:P; applied for Oct. 11, 1326; ai-ie t1o Laucks Labbra`o- Inc.

Fr-jJt such as apples, pears, auinc, pl:as, 0r1ne.f, orangeos,
gralcmfm.it, lemons, etc., is washed vi-h ua to 7-) pvrcen>t
solution of trisodin'mi phosphate to re-ov3 rsrc rosidacs of
lead arsenate, c lcium arsenate, borC...x.ux m1-.iVc, Sul.hj:r mray,
nine'al or vegetable oil spri ys, etc. tl-x.... salts of IO'7
nlkalinity, o ., scdi ort an sodiurmm .and pc ssiu:.i
carbor-itos, may also bo used in soluticrs of such strength as
not to exceed the dogroe of iakalinit; of 10 percent trisodirm
p o-0phsatc. In general, this vould. irCLude alkaline salt solutions
having a pPI of not greater than 13.

LIP .A'. J. .2

MPO:T 0]- Tr^ D" -,OE, -0. J. AEr. t Sta .A.n. RIt. 19o 7
1929. pop. 1-72. 1930.

Renartless o- the w.antit- of lead arenate an-plied, on fall
and winter varieties of anpl-s, v;hen sprays were not addiwd after
Jv.ly, arserical -esidues lid not e-xceed 0.01 grain of arsenic
trioxide per pound of fruit. Sprays applied later than July 1
resulted in heavier residues, T.he-i co-er spr' .' l!,ter than
JTuly 1 are imperative, dust iE-,. be safely used.

Laboratory and practical tests have shown thet dilute h.-.'.ro-
chloric acid (0.3 to 1.25 percent) is the most efficient solvcni-
for the rei,.oval of spray residues. For .,he grol'cr having only
a small lot of fr it to bo cleaned, hard-dioping the frut has
-been found. practicu0olc,






- 84 -


LIST, G. M. (288)

A CHERRY TEST IN COLORADO. Colo. Agr. Expt. Sta. aBull. 385.
106 pp., illus. 1932;

Analyses made of cherries from experimental spray blocks
to determine the amount of spray residue on harvested fruit
showed that most of the samples carried more than the proposed
tolerance of 0.01 grain of arsenic trioxide per pound, one
having 0.04 grain. The handling and washing of the fruit at
the canning factories removes some of the residue. No samples
of the canned cherries carried more than 0.01 grain per pound.
The later applications left the most residue. It appears that
thi:ee sprays can be used only on fruit that is to be carefully
washed at the factory. Fruit to be sold fresh should not re-
ceive more than the first two sprays and 1 lb. of lead arsenate
to 50 gals. of water should be the maximum strength. There is
little dcubt that washing in dilute (1 percent) hydrochloric
acid would remove the arsenic below the tolerance. This would
probably rot be practical for cherries going to market as
fresh frait buT could be developed for use in factories.

LUTZ, J. M., and RJi-T:ER, G. A. (289)

STUDIES ON THE L'MOVAL OF ARSEIICAL SPRAY RESIIUE FRCM GRAPES.
Amer. Soc. Hort. Szi. Proc. 1932: 345-349. 1933.

Results of eYpmriments indicate that grapes can be
successfully w.shied in a juice plant for removal of arsenical
residues in most cases with only slight modifications of present
practices. As a wash solution, hydrochloric acid not stronger
than 1 to 1.3 percent should be used and it should be followed
by a water rinse. With gra-pes to be packed for shipment, it
would be prefer-ible to reduce the arsenical load below the
tolerance by modification of the spray schedule. If this is
irxpossible, grapes can be w-.shed and shipped wet provided they
ara carefully handled and ire packed in baskets of 12 qt. size
or less.

MA&S, A. R. (290)

PROCESS OF REMOVING LEAD AR-SEITATE FROM FRUIT. U. S. patent
1,754,173. Issued Apr. 8, 1930; applied for Dec. 21, 1926.

Lead arsenate spray residue is removed from apples, pears,
etc., by washing or spraying the fruit with a solution of more
than 1 lb. (preferably 3 to 5 lbs.) of sodium thiosulphate in
a gallon of water for a period of 1 to 10 minutes. The ad-
. edition of soap or alkali will assist in wetting the fruit and
penetrating any oil present. Any thiosulphate calpble of dis-
solving lead arsenate may be used, e. g., potassium, ammonium,
or calcium thiosulphate, the proportion used being varied according


-ft.






- 85 -


to the molecular weight. After this treatment the fruit is
well washed. with water and allowed to dry.

McLEAN, H. C. (291)

SCI REESSULTS OF A STUDY OF SPRAY RESIDUE OK APPLES IN 1927.
N. J. State Hort. Soc. Proc. 1927: 213-225.

Mechanical cleaning machines are unsatisfactory as re-
movers of arsenical -residues because they cannot reach the stem
and calyx cavities. The chemical removal of spray residues has
been investigated. Preliminary tests were made with washes of
Sacetic acid, sodium hydroxide, and hydrochloric acid. The last
gave the best results. Laboratory tests show that hydrochloric
acid.in concentrations as low as 0.5-percent, with 5 minutes of
contact, will remove arsenical residues satisfactorily, provid-
ing the fruit is not too ripe and waxy, no matter whether dry
mix or lime sulphur, Kayso or flour is used in the spray
formula.

----., (292)

SOME FACTS ABOUT APPLE SPRAY, ESIDUES.. N. J. Agr. 11 (4): 10.
1929.

T:ew Jersey experience indicates that dilute hydrochlor-
ic acid (0.3 to 1.25 percent) is the most efficient solvent
for the removal of spray residues.

---- (293)

EXPERIE1:CES WITH THE SPRAY =SSIDUE PROBLEM. Del. Bd. Agr.
Quar. Bull. 20 (5); 82-89. 1931.

Washing of apples or pears with dilute hydrochloric
acid has proved the most satisfactory method for the removal
of spray residue. Two gallons of 20 Be. acid to 100 gals.
of water was found necessary for varieties of apples maturing
before Vealthy, and 3 gals. of acid to 100 gals. of water for
Wealthy and later varieties. The home-made paddle washer,
the Bean chemical washer, and hand-dipping are suggested as
methods of washing.

---- (294)

THE EW7 LEAD TOLERANCE AND HOW TO MEFT IT.. Amer. Fruit Grower
53 (5): 7, 11. 1933.

The use of a textile wetting or degumming agent such as
Vatsol or Alkanol B in conjunction with the hydrochloric acid
wash has been found to greatly increase the efficiency of lead
removal from oil-lead arsenate sprayed apples. The mixture
used by the New Jersey experiment station consists of 5 gals of
20 Be. hydrochloric acid and 8 lbs. of Vatsol to 100 gals. of








- 86 -


water. In the treatment of oil-lead arsenate sprayed but not
excessively waxy fruit, Alkanol B proved a satisfactory substi-
tute for Vatsol, when used at the rate of 4 lbs. of dry powder
to 100 gals. of water.

----- and WEBER, A. L. (295)

USE OF WETTING OR DEGUTMMING AGENTS IN THE REMOVAL OF SPRAY
RESIDUES FROM APPLES.' Jour. Econ. Ent. 24: 1255-1261. 1931.

Textile wetting or degumming agents used in conjunction
with dilute hydrochloric acid. or a mixture of dilute hydro-
chloric acid and salt, will satisfactorily remove residue from
New Jersey apples receiving heavy applications of oil and lead
arsenate sprays. In most cases the application of heat to the
cleaning.solution was unnecessary.

and WEBER, A. L. (296)

MODERN METHODS OF REMOVING SPRAY RESIDUES FROM APPLES AND
PEARS. N. J. Agr. Expt. Sta. Ext. Bull. 87. 24 pp., illus.
1931.

The time of application of sprays has a more important
bearing on residues than the quantity of spray material ap-
plied. The relation of spray schedules to spray residues for
varieties maturing at different dates is shown graphically.
Considerable difficulty with residues may be experienced in
orchards where early and late varieties of fruit are inter-
planted, as the carrying over of sprays results. Rain may
cause the accumulation of residues by gradual washing of spray
material from upper portions of the trees.

Present types of mechanical machines are unsuitable for
removing spray residues. Washing methods using water as a
solvent are but slightly more effective theman is wiping or
brushing. Removal of spray residues by washing with hydro-
chloric acid has proved practical and economical. In gen-
eral, the solutions should contain 0.63 or 0.95 percent acid
(actual HCl) (2 or 3 gals. of 20 Be. acid to 100 gals. of
water). Fruit may be cleaned in dilute acid by hand dipping,
with a home-made paddle washer, or with one of several com-
mercial chemical fruit washers, depending on the individual
needs of the grower. Construction plans and directions for
the operation of home-made washing equipment are given.

---- and WEBER, A. IL. (297)

THE RESULTS OF SrPRAY RESIDUE STUDIES ON VEGETABLES IN 1932.
N. J. State Hort. Soc. News 14: 490-491. 1933.

It was found that high-residue cabbage and cauliflower
would meet the market residue requirements if trimmed suf-








- 87 -


ficiently. Residue on canning tomatoes was satisfactorily re-
moved with water by the use of the usual washing equipment in
two establishments.. Removal of residue from heavily sprayed
Early Red Pear tomatoes was possible by submersion in 1 per-
cent hydrochloric acid solution without injury to the fruit.
The following precautions should be observed to avoid heavy
residues on vegetables:

1. Control insect pests, if possible, when the plants
are small.

2. If late sprays or dusts are imperative, flour, lead
arsenate, or bordeaux should not be included in the mixtures.

3. In applying arsenicals to cauliflower after the
flowers or head have commenced to form, protect the head in
some manner.

4. Late sprayed or dusted cabbage should be trimmed to
two loose leaves.

5. If necessary to control insects on celery after the
plants have matured, use oyrethrum or some other material non-
toxic to humans.

and 7E3ER, A. L. (298)

CLEANING OF FRUIT CARRYING LEAD. Science 78: 570. 1933.

Within the past two years the authors have developed a
method of using a wetting or degumming agont of certain types
with hydrochloric acid which would enable fruit growers to re-
duce the arsenic and lead residues on their produce to the
required tolerance. More recent experiments show that these
wetting and degumming agents, when used with alkalies and
alkaline silicates in heated solution, increase their effi-
ciency to a marked degree. Fruit carrying lead 12 times
the federal tolerance of 0.02 grain per pound' was satis-
factorily cleaned with the silicate-wetting agent wash.

---- and WEBER, A. L. (299)

METHOD OF REMOVING SPRAY RESIDUE FROM FIJIT. U. S. patent
2,003,005. Issued May 28, 1935; applied for Oct. 27, 1933.
Assigned to Endo07Ment Foundation.

A method of wishing fruit and the like to remove spray
material from the surface thereof includes applying to the fruit
solution containing about 1.0-2.0 percent of hydrochloric acid by
weight, about 0.50-1.0 percent of a sulphonated aromatic hydro-
carbon, and not over 0.5 percent of a substance adapted to prevent
foaming of the solution. While a considerable number of sub-
stances of various types may be used for this purpose, we find
that substances taken from the following class, aliphatic ketones








- 88 -


and alcohols having from 6 to 10 carbon atoms, pine oil, fusel
oil, degras, naphtha or mixtures thereof, usually in compara-
tively small amounts, produce anti-foaming effects.

-- and WEBER, A. L. (300)

INFLUENCE OF SPRAY SCHEDULE AND OTHER FACTORS 01 SPRAY RESIDUE
REMOVAL. Jour. Econ. Ent. 27: 168-179. 1934.

When oil is not used in combination with lead arsenate in
the spray schedule, in addition to a casein or colloidal protein
type spreader, all varieties of apples may be sprayed up to time
of harvest and the residues removed with cold hydrochloric acid.
Varieties of apples maturing before Wealthy may bo sprayed with
the oil-lead arsenate combination 27, 37, 47, 57, and 67 days
after petal-fall, using a non-casein spreader, and be satisfac-
torily washed in any type of washer if a wetting agent (Vatsol)
is added to the hydrochloric acid washing solution. Acid alone
will successfully wash fruit where oil and lead arsenate are ap-
plied no later than 57 days after petal-fall. Wealthy and later
maturing varieties may be satisfactorily washed in hydrochloric
acid alone if oil-lead arsenate sprays (3 qts. and 2 lbs. to 100
gals.) are applied no later than 57 days after petal-fall. Where
similar applications are made 67 and 77 days after petal-fall, the
addition of a special wetting agent to the acid is essential. Sat-
isfactory washing may be accomplished at atmospheric temperature,
although the operating speed of commercial washers may have to be
reduced. Pre-dipping the fruit for 1-1/2 minutes in a vat contain-
ing the acid-wetting agent wash before passage through the commer-
cial washer makes it possible to maintain the regular speed of the
latter. The use of any later sprays of lead arsenate and oil in
the concentrations stated above may necessitate heating the wash-
ing solution. Applications of lead arsenate and non-casein spreaders
without oil after the 67-days spray do not affect the above recom-
mendations.

---- and WEBER, A. L. (301)

SPRAY RESIDUE REMOVAL FROM FRUITS AND VEGETABLES. N. J. Agr.
Expt. Sta. Ext. Bull. 122.7 pp. 1934.

This bulletin is a supplement to Extension Bulletin 87,
which was issued before the Federal lead tolerance was promul-
gated and before the use of oil-lead arsenate combinations for
codling moth control had become general.

In the absence of oil in the spray schedule, apples or
pears may be easily washed with 1 to 1.5 percent hydrochloric
acid as soon as they are harvested. Oil applied with lead ar-
senate for second-brood codling moth may necessitate the use
of a textile wetting or degumming agent in conjunction with
the acid. In this process, 5 to 5-1/2 gals. of 20 Be. hydro-
chloric acid and 2 to 8 Ibs. of wetting or degumming agent are







- 89 -


added to 100 gals. of water. When used in a commercial flood
or spray type washer, the violent agitation of the solution
causes excessive foaming. This can be controlled by the
addition of a defoaming agent, e. g., a 50 percent solution
of purified degras in purified naphtha used at the rate of 1 1/2
pints to 100 gals, of wash solution. This washing treatment
has boon most successful with the home-made flotation washer,
exposing the fruit to the solution, at ordinary summer tempera-
tures, for 1 1/2 to 2 1/2 minutes. In most flood or spray type
commercial washers used in New Jersey, the fruit remains in
contact with the wash solution for only 24 to 45 seconds. Under
some conditions, with oil-lead arsenate sprayed apples, it is
then necessary to heat the solution to 1000 F. to remove lead
residues. In many cases the necessity for heating has been
eliminated by reducing the speed of the washer or by using a
predip tank, in which case the fruit is washed for 1 1/2 to
2 1/2 minutes in the acid and wetting agent mixture, then passed
through the commercial equipment for rinsing, polishing and
drying.

There is no Federal tolerance on copper residues, but
in some cases enough bordeaux residues are left on produce
to impart a disagreeable coppery taste. Such residues may be
removed from grapes and small fruits, as well as beans and
tomatoes, by dipping in acetic acid (I gal. of glacial acetic
acid to 100 gals. of water) for 1 to 2 minutes, draining and
rinsing. Hydrochloric acid will not remove bordeaux mixture.

To remove arsenic from small fruits, beans or tomatoes,
a solu-tion of 3 gals. of 20 Be. hydrochloric acid in 100 gals.
of water, in which the produce remains for 1 minute, is
effective. It is not practical to subject such vegetables as
cabbage and cauliflower to chemical washing. Because of the
manner of growth of these vegetables, the problem may be
solved by trimming. To avoid heavy residues which necessitate
drastic trimming, control insect pests, if possible, when the
plant is small. If necessary to control insects on vegetables,
including celery, after plants are nearing maturity, use an
insecticide non-toxic to humans.

.---- and WEBER, A. L. (302)

HOW TME STATE OF NEW JERSEY MEETS THE SPRAY RESIDUE SITL.TION.
Del. Agr. Bd. Quar. Bull. 23 (5): 43-50. 1934.

The New Jersey method of cleaning fruit employs the
following mixture: 5 to 5-1/2 gals. of 20 Be. hydrochloric
acid, 8 lbs. of Vatsol and 100 gals. of water. The efficiency
of this depends somewhat on the type of washing machine used.
The various types are briefly discussed.







- 90-


a~, vT r


303)


ivAGN3


(304)


THE REMOVAL OF SPRAY F.7SIDUE FROM FRUIT. Better Fruit 22 (12):
7-8, 20. 1928.

Dry cleaning is less satisfactory than washing. Hydro-
chloric acid is suitable for cleaning. The concentration of.
acid required increases as the fruit becomes oily from stand-
ing in storage. Concentrations up to 2 percent were used in
1927 Raising the temperature of the solution increases the rate of
cleaning. Thorough rinsing is important.

Alkaline solutions are equally as effective as acid in
removing the spray residue. Solutions of soda ash are general-
ly used when the residue is -not ton difficult to remove, With
heavily sprayed lots, soda ash w*ith sodium hydroxide or caustic
soda of 0.25 t'o 0.5 percent strength? was used. In commercial
use of this method in 1927, borax was added to the washing
solution in addition to soda ash and the solution was heated
to 80 to 110 F. Coating the fruit subsequently with oil and
paraffin prevents shriveling due to attack of the natural wax
by the alkali.


REMOVAL OF, SPEAY RESIDUE, FROM'APPLES AD'.PEARS. Idaho State
Hort.,Assoc. Proc. 32: 77-85"' 1927. ., .
Wiping of pears-and apples is unsatisfactory for removal
of spray residue. Washing with hyvdrochloric acid has been found
most successful by all agencies conducting tests. Sodium
hydroxide was found efficient but.it .is harder~to rinse from
the fruit and more likely to be i'jurious than hydrochloric
acid. Nitric acid also*proved generally satisfactory but it
is more expensive, more corrosive and more dangerous to.
handle than hydrochloric acid.. The Colorado Experiment Station
suggests the use of 4 percent soda ash and4 porcont ordinary
salt solution at 1000F.

One part commercial hydrochloric acid of 200 B. by
volume to 100 p-irts of water (0.365 percent HCl) is sufficient
acid concentration to effectively remove lead arsenate .
residue from fruits. If an immersion system is used, 5 to 10
minutes is required. If acid jets are employed,- the time is
much shorter. Temperature control is not necess-iry. Thorough
rinsing should follow. If an abundant' supply of fresh water
is not available, bicarbon-.te ef soda may be added to the rinse
in amount just sufficient' to keep the solution -from becoming.
acid.,


/,







- 91 -


---- (305)

CLEANING !AXY OR OILY FRUIT. Better Fruit 22 (8): 20-21. 1928.

Heat is necessary with both acid and. alkaline washes
for cleaning fruit which becomes oily in storage. Temperatures
up to 110 F. and acid concentrations of 3 percent did not
injure Winesaps and Arkansas Blacks.

--- BLACK, 0. F., and HALLER, M. H. (306)

DIRECTIONS FOR USING HYDROCHLORIC ACID SOLUTION FOR REIOVING
ARSEIATE CF LEAD RESIDUE FROM APPLES AND PEARS. Bur.
Plant Indus., U. S. Dept. Agr., Mimeographed report. Illus.
4 pp. (i7o date, but issued 1926-1927.)

Diagrams and brief directions are s-iven for the con-
struction of a washing tank and rinsing tank. As a wash
solution, 1/3 to 1/2 percent actual hydrochloric acid (1 to
1 1/3 gals. 20 Be. acid to 100 gals. water) is satisfactory
Thorough rinsing of the fruit must follow the acid wash. If
at least 2 gals. of water for each box of fruit is not avail-
able for the rinsing tenk, bicarbonate of soda must be used
to keep the water from becoming acid.

. ., OVERLY, F. L., HEALD, F. D., TELLER, J. R., (307)
FISHER, D. F., and DIEHL, H. C.

THE REMOVAL OF SPRAY RESIDUE FROW. APPLES AiD PEARS IN
WASHINGTON STATE. Wash. Agr. Expt. Sta. Pop. Bull. 142.
29 pp., illus. 1928.

The number and strength of lead arsenate sprays shcild
be kept down to the minimum in order to reduce the amount of
residue on the fruit at harvest time. Experience indicates
that the use of casein spreader or oil with the arsenate of
lead makes the residue slightly more difficult to remove
chemically. Where hydrochloric acid is used as the cleaning
agent, the use of lime with lead arsenate spray may have con-
siderable merit.

Three types of dry cleaning machines and eight types
of washing machines are illustrated and discussed. In general,
chemical: cleaning is more effective than dry cleaning methods.
Hydrochloric acid can be used satisfactorily for washing apples
to remove lcosd arsenate residue and considerable fruit has been
cleaned commercially by this method. The loss agitation there
is applied in the washing, the loss effective the cleaning is
unless longer exposuresarc given. A driving jot of acid
solution striking the fruit under considerable pressure proved
very effective. The application of spra-r or flood wash without
rotation of the fruit was slightly less effective than a








- 92- -


similar treatment with rotation. The system in which the
fruit was floated, in the acic. solution with sprays striking
the fruit and driving it. forward generally involved an exposure
to the acid of about 3 minutes. Fruit treated with a minimum
of agitation, as when immersed in boxes., can be efficiently
cleaned only if rather long exposure is given.

The strength of acid used varies with'the condition
of the fruit and the amount of residue. Fruit carrying not
more than 0.03 to 0.04 grain of arsenious oxide per pound,
being treated immediately after harvest, can usually be
cleaned satisfactorily with a solution containing 1 gal. of
commercial hydrochloric acid to 100 gals. of water (about
0.36 percent by weight). After the fruit becomes oily as
a result of standing in storage, the residue becomes harder
to remove and higher concentrations or higher temperatures
or both are necessary. After the fruit leaves the acid bath,
it should be thoroughly rinsed, preferably with fresh running
water. The following points are important in avoiding injury
of the fruit by the acid wash: (1) Cleanliness of the bath;
(2) reduced penetration of the acid by avoiding submergence of
the fruit as much as possible and avoiding a driving acid wash;
and (3) thorough rinsing with fresh water. Where at least 3
gals. of fresh water for each box of fruit is not available, the
use of lime in the rinse water is recommended.

Alkaline solutions are as effective as hydrochloric
acid in removing spray residue. A solution of 1 to 2 percent
soda ash has boon generally used when the residue was not too
difficult to remove. With hoav.ily sprayed lots, sodium hydroxide
or caustic soda sufficient to make a 0.25 to 0.5 percent solution
was also added. In commercial use of this method borax was used
in addition to the soda ash and caustic soda and the solution
was heated to 80 to 100 F. Alkaline solutions generally are
more difficult to rinse from the fruit than are acid solutions.

If the fruit is sound and rinsing is thorough, there is
relatively little need for complete drying.

MARSHALL, G. E. (308)

1934 CODLING MOTH SPRAY TESTS. Ind. Hort. Soc. Trans. 1934.
62-65. 1935.

The same washing solutions and methods successful in
lead arsenate removal will not necessarily suffice for the
cleaning of fruit sprayed with copper, zinc, fluorine, or other
compounds having a tolerance set by the U. S. Food and Drug
Administration. Loads as high as 0.55 grain of lead per
pound of fruit wore encountered, and the removal in such cases
was not entirely satisfactory with the best solutions known
and the application of heat. Such loads wore reduced, however,
to 0.02 grain per pound.






- 93 -


I1 ARSEA1L, R. E. (309)

LT^ IG-^-HOV/ A17D 7THE? Yrritc an.d C-rdOen. 28 (6): 5, 15.
1930.

The situation. i:' the Pacific Torthw.st is reviewvd.
Dilute hydrochloric acid, 5 to 7 quarts of comncctrcAted acid
to 100 gals. of wrp.tr, is -reco.neonded for washi g in nost
cases. Late in the season, it is sometimes necessary to use
10 or 12 quarts to 100 gals. Thorough rinsisg is necessary.
Hydraterl. lime is soletir.es addel to the rirse wVater, especially
when water is not abundantly available for rinsing. Drying is
accomplished by bloolers or torel drapers.

o1001, H. C. (0)

SPIAY i:ASI:^ AND THE P"U-K FOOD LAW. 17.? Vh. Sta-e -Hort. Assoc.,
Proc. 28th Ann. I:,.eting 1932: 123-131; dCaho State- Hort. Assoc.
Proc. 38: 107-111. 1933.

Soda ash, crude alkali earths, sodiwim triphosphate,
sodium netasilic-te, and other ill-,1es have been employee. in
place of hydrochloric acid for the removal of le.d arscnateo
residues. All are less effecti:-; than hydrochloric acid for the
removal of lead..
*
The ultimate hope is to ortrcl the t in a way that will
not render the pro-duct poisonous to inf:-is. The recent
extensive use of fluorine comnounds, which are now known to be
highly toxic to iman, has further complicated the situation.

HULVATY, H. A., and .:E::i-Y, H.E. (.EI)

P?-.CCSS AlT-- APPARATUS _-C?- CLZlIGC :-'U: T. U. S. patent
1,916,633. Issued July 4, 1933; applied for September 2.,
1929.

A blast of material such as sawdust is used to remove
lead arsenate resicduei frcom fruit and to polish t..e fruit.

TLLER, J. R. (312)

SPRAY RESIDL-E EiiOVAL F20L: APPLES. Wash. State Hort.
Assoc. Proc. 22: 28-36. 1926.

In -iir., cases dry wiping of apples vwill not reduce the
arsenical residue to the desired level. SproaOrs had no
effect on the ease of removal. Oil in the spray sch.:dule
increased the difficulty of removing resid-oes by dry wiping.
A number of solutions were tested for the removal of arsenical
residue by washing the fruit. Jonathan a les carrying an
avera're load of 0.071 g,:dti of arsenic trioxide per pound were
soaked for 5 minutes and brushed for 20 seconds in water alone.






94-

'h. residue was cuit to 0.021 Z-UI p-r poumn. Alcohol fn&
acetone [in water] wore found ireffectivc. The alkalies such
as amrionla and sodiuLi hjdro.-ide did not remove as much of the
resi d.e ac the .cis. .T tric, hydlrochloric and 3ul -huric aciCI
were i.bout equally effective, Uuch more so th.'Ar. acetic and
s-JPhuious acids. Th. use of svlphuaic aind acetic acidk was
6.iscontinued bceaise of observeC injuries to fruit in torage.
ihitric acid was known; to be corrosive to 7;iaclhi.ery aind
operators. For the purposes desir,-, hoadrochloric acid
appeared to be the bc.t che:ic .l to ise. Prolir-Anary tests
shored that a 1 percent .olutio) of this acid at a temrerature
of 70 F. could be expected to remove recid(,es sufficiently
by brushing the fruit i. t'he solution for a'out 20 seconds.
The t;.pe of washi-ig machine used is described.



L-.Sl-rICAL ESIDrLE OF FPTJITS. '\7'ash. Ar. -" t. Sta. Bull. (313)
229 (A-m. Ept.):21. 1: 3.

The acid c i_' solu'Vton ;a-. more effective on waxy
apples 7whcn hatedr to a'borLt 10 P'. It vt not necessary to
hcat the solutions for cljci; l ,rI : -C .to rcsidu-, from
pears. A study of the accunlii.ltior of arso-ic in the clcariing;
solutions showed. ho importinco of chvgi.in. the solutions about
once a day.. Very v-axy- fruit culr' bo cla:.cd without harm
if dipped in noynto-ic waz solvent -oprevi'us to tae acid wash.

(314)

CH-LU'GS PPODC2D ;I F'PILFS BY TE3 L'US OF COZA:1i! TD OIL-
COAI.. P.....S.S. .Jour. Agr. Res arch g, :429-436. 1 .

Dipping in 2 jrorcot hydrochloric acid at 200 C, with
mild agitation for 10 ninutoes had little offoct -.i,,:n theo
subsoquient rates of c 'tlrr carbo-i dioxide rcs-iration or loss
in. weiht of Winrssap "pplcs. Dip)-)inc in 2 percent sodium i- iro::ido
un1Oer the sarc cDndcitions affoctod. r. r.i r'aioi slig:tA,- and1 1i-
crcacsed tho rate of loss i wei '.

(1.15)

i.;.OYL OF 3SPFL'Y S.CSLjS ;lir..APPI2S. 1A 'J!LX SOL~vE.T MTHOD.
Indus. and Zriin. Chom. 2:323-S25. 1931.

Hydrochloric a.cid is an effective cl"ani.n 't for
apple in most cases, but it sometimes fails with fruits that
have been oil-spray-ed or tnat have beco-e waxy. It is shown
that a thorough clran-'n car. be obtained by firs; dipping the
apples in certain wax solvents, preferably methanol (acetone,
petroleum ether and diacetone alcohol were also tescrl), after
which an munheated hydrochloric acid wash is able to dissolve
and rLMove practic-,,lr all the lead arsonate rcsouce.







- 95 -


1I T7C0I.Ej, J. J., and CARTER, R. H. (313)

STUDIES OF FLUORII COiPOUlkDS FOR CCTF.OLLT__G TiE CODLIlHG
IOTH. U. S. Dort. Agr. Tech. Bull. 373. 23 pp. 1933.

Samples of Winesap apples sprayed with batrium fluosilicate
were taken before and after each spraying and at harvest and
analyzed for resides. ITo standard procedure was available,
so a method was developed (PT. H. Carter. Indus. z;J':-i. Chem.,,
Anal. :Ij. 3: 146-147). The results are given in mg. per arple
and cg. ner sq. cm. and are compared v with analyses for arsenic
of a.:ples sprayed throu hout with lead arsenate.

Tests were made to determine the feasibility of removing
residues of barium fluosilicate from the fruit bby means of
chemical solvents. Starting .ith fruit with an average deposit
of 0.04 grain of fluorine nper lb., treatment with 1 percent hyd.ro-
chloric acid, in a flood machine, at 75 F. reduced the load to
0.009 grain per lb., at 90 to 0.006 grAin per lb., and at 110
to 0.005 grain per lb. Wa *'rg with 1 percent sodium carbonate
at 90 and 110 F. r suited in. an avrage deposit of 0.014 grain
per lb.

Fruit that had bbeen s-. r:;-co with cryolite was washed,
after several monthss of storage, with 1.5 percent hydrochloric
acid at 110 F., with 5 r .-rccnt sodium silicate at 120 F.,
and with 1- percent sodtiu, carbona'te at 110 F. This fruit
had a maximum deposit of 0.022 grain of fluorine per lb. before
washing. Treatment w'ith hydrochloric acid resulted in an
average deposit of 0.004 grain l&er lb.; with sodium silicate,
of 0.007 grain per lb.; and with sodium carbonate, of 0.015
grain per lb.

Q1TOTEC L., and OTL2\, F. L. (317)

A ESLUIE OF SPIiAY E SIDU iE OVAL .EXP-I:C. S I- TH STATE C7
UASEIUIGT01T. Better Fruit 29 (1): 3-4, 15. 1934.

7ith one spray program, certain lots of fruit with a
light load of lead or arse:ic are often more difficult to clean
than fruit receiving another spray -orogra and. having a residue
several times greater. `her manganese arsenate sprays were
used, hydrochloric acid was more satisfactory as a washing a,;ent
for arsenic removal before the wax formed on the fruit to any
apprcciablc extent, but the load was more satisfactorily rCemoved
with sodium silicate. Later in the season, after wax had
developed, it was necessary, with fruit sirilorly spiry-ed, to use
a tandem:n wash of hydrochloric acid and sodium silicate to
successfully reduce both the lead and the arsenic. When
calcium arsenate combined w-ith oils and spreaders was used
throughout the season' hydrochloric acid was a m:iore satis-
factory wash than sodiuni silicate. Arsenic residue was effectively
removed from Delicious apples sprayed with zinc arsenate and






- 96 -


iurring oil oy cith.r hydrochloric acid or sndiiu, silica.t'.'.
Tho ur of `,uorirrc "p:- y-.,s in adt'iti.on to load c.1rs.-.nate, in
corbiration with other -,atcri.-is, s cO,..d to incr:a,3o the prjblrn
of rer-oval of :.rscnic- and lead., Th; uoc of fis'. oil in err .'-s
tmndr-d to ,crc-' tihc offoctivoness of sodium !ilic-l.te it,! -G,
removal of both _Lrs3nic and- lead and did not -generall,- mai.O
cleaning with hydrochloric acid more difficult, 1..neral oil
caused ircrc.ised ('ifficulty in cdcarinJ with hydrochloric a-i(
but had little effect o.- cleaiin- with sodiuzi silicate,. Ticotire
s1lphato and mineral olI combinations for. socond-brood sjpra.y,
following heavy applications of Ic:.i arv-on,.t for first brood
complicated rosidi.e rcn.val, but no more go tLan mineral oil
without ricoti e. ?Fi s oil caused less di"cuty th+n the
mineral oil, especially when sodium silicate was us.d for
-.ashgl.g. Soan- type spruadcrs added to the s-,rar inc.'Ia.: (
the difficult in cleening with hydrochloric acid but facilitated
cleaning with sodiumi silicate.

Sod.i"m silicate '-c!s more efficient as a wash at hi-hD.r
temperatures nd .owcr ..oncen.rat.ons :,ha., at hirhcr concrn-
trations and lower termooratrrcr. 7ith this a fent it was
necessary to develop adeq-xi.te foaxn, rnd soap was an excellent
means for that parpose. :.erosene was satisfactory to control
excessive foaming. Hydrochloric ac.d was more satisfactor-
than sodium silicate rith fruit :.r:,.;"e<. with manganese arsneite,
calcium arsenate, load ar-..r.ate-Limo, or wi th early harvete,'.
and oarly .w.shed t rait sF_: ..::d 'Jith load arsenate alon. 7i th
fruit spra-yed with loead arscnato and mineral oil, ind early
harvested and early washed, sodium silicate, in a suitable
machine, wias as effective as <.L''ochloric acid.. 7ith fruit
sprayed with fish oil-lead arsenate and with lEad arsenate-
mineral oil, or with lead arsenate alone, harvested late and
washed after wax had developed, sodium silicate w-ith soao was
superior to hydrochloric acid. Tandem washes were used with!
general success.

-- -- OVPI-EY, F. L., and ST. JOHiIT, J. L. (LIS)

SOliE OBESRVA1I0Oi.S Cci:C:.7...:, SPRAY P:.SILUE' REIDVA.L :1: 193".
Vlash. State Hort. Assoc. Proc. 29th Ann, Meeting 1?33: 7A-41.

Hydrochloric acid is more satisfactory than sodium il.icite
for clemUiing fruit sprayed with i;n>anar manganesee ar-enate),
calcium arsenate, lead arsenate combined with lime, or with
early harvested and early washed fruit spr.,.-ed with lead arsenate
alone. '7ith fruit spr_-t-cd with lead arsenate and mir'cra]l oil,
and early harvcstod and early washed, sodium silicate, when used
in machines permitting its effective use, was equally as effective
as h-ydIrochloric acid. Tith all fruit sprayed with fish oil-lead
arsenate and with fruit sprayed with lead arsonate alone, loeiW
arsenate and mineral oil, harvested late and. wrishcd after wax
had. d.cveloped, sodium silicate was superior to hydrochloric
acid. 7Then sodium silicate was usc.d to rcnovo fluorine sprays








- 97 -


from apples there was much less likelihood of injury from wash-
ing than when hydrochloric acid was used., When tandem sprays
-ro used to clean fruit spr-yced with fluorine compounds, it
seems advisabole, in order to mirimizo the danger of injury, to
use sodium silicate ahead of the hydrochloric acid. When used
to clcr.n fruit sprayed with lead arsenatc, excellent cleaning
may result with either sequence. With waxy fruit sodium
silicate nay be most effective first, so that the wax will not
seriously affect the acid. From the point of view of appearance
and condition of the fruit after washing, ho.'ever, it seems
generally advisable, wherever feasible, to use the tandem
sequence of hydrochloric acid first and sodium silicate last.

O-J rLY, F. L., and GARVER, H. L. (319)

RESIDUE PEi:OVAL AHTD ITS RELATIO TO TIHE SPRAY PROGRAM AND
ORCHARD GROWING CONDITIONS. Wash. State.Hort. Assoc.,
Proc. 28th Ann. Meeting 1932: 89-101.

Results of wach:'ng fruit with 1.5 percent hydrochloric
acid, soda ash (50 and 75 lbs. per 100 gals.), trisodium
phosphate (50 and 75 lbs. per 100 gals.), and sodium silicate
(50 and 75 lbs. per 100 gals.), all at 110 F., are reported.
The acid gave about equal results with high and low lead arsenate
spray programs, but with the alkaline solutions either the con-
centration or the temperature had to be raised as the lead
arsenate was increased in strength. When the amount of fish
oil in combinaiion with the lead arsenate was increased, the
removal of arsenic with trisodium phosphate and sodium
silicate was improved, but with hydrochloric acid and soda
ash it was more difficult. Fruit sprayed with mineral oil-
lead arsenate combination was more difficult to clean than fruit
sprayed with straight lead arsenate, especially when hydro-
chloric acid was used for cleaning. Fish oil in the mineral
oil-lead arsenate spray facilitated removal of arsenic with
trisodiun phosphate and sodium silicate. The addition of
kerosene emulsion to the alkaline solution and. a kerosene pre-
spray in combination with the alkaline washes incre sed the
efficiency. The same pre-spray followed by acid caused a
serious lentic-l burning of the fruit.

Only 3 out of 10 sanplos washed with 1.5 percent hydro-
chloric acid at 1100 F. were cleaned below the 0.01 grain tolerance.
Soda ash at a concentration of 75 lbs. per 100 gals. at 110 P.
is fairly satisfactory with the average sample, and is generally
as effective as higher concentrations. Trisodium phosphate
was the most efficient washing material when fresh solutions
were used, In a range of 75 to 100 lbs. to 100 gals, the
addition of 1 qt. of odorless kerosene facilitated cleaning.
There is some question as to the length of tine trisodium
phosphate can be used as a wash. Every lot of fruit tested
was satisfactorily cleaned with some concentration of sodium
silicate at a certain to-?pcraturc.








- 98 -


The amount of arsenate on the fruit at harvest time
is not a true criterion of difficulties that may be en-
countered in cleaning. It has generally been found that
where hydrochloric acid was used for arsenic removal, the
longer the fruit was held in common storage, with the greater
development of wax, the more difficult it would be to wash.
There is not much difference in the cleaning Of' fruit held
in common or cold storage when sodium silicate is used. Heat
is necessary with the alkaline solutions.

---- and ILLER, J. R. (320)

EXPERIEi:CE IF SPIAY RESIDUE BREHOVAL. Wash. State Hort.
Assoc. Proc. 2: 126-130. 1927.

Spraying of apple trees with a water solution of lye
and soap 5 to 7 days before harvest did riot appreciably lower
the ar'-eni eal residue at harvest time. In a comparison of
acid and alkaline washing and dry wiping, the acid wash gave
the best results and dry wiping the poorest. Different brands
of lead arsenate and & different combinations with oil and
spreaders seem to cause a variation in the ease of residue
removal. The use of pressure with the acid spray in washing
facilitates the removal of residue but may cause injury to the
fruit. Increasing the temperature of the acid solution is
important in reducing residue on late varieties. 'Increasing
the strength of acid is not as important a factor as increasing
the time the fruit is in the solution.

--- OVERHOLSER, E. L., and ST. JOHN, J. L. (321)

1933 WASHING EXPERIL1TTS WITH SPECIAL REREEE'CE TO IEW SPRAYS.
Wash. State Hort. Assoc., Proc. 29th Ann. Meeting 1933: 79-85.

7hen manganese arsenate, 3 lb$. to 100 gals., was used
throughout the season in six cover sprays in combination with
dogfish oil or linseed oil or with mineral oil emulsified
with casein ammonia, the arsenic residue on Delicious apples
was more difficult to remove with either hydrochloric acid
or sodium silicate than when fruit was sprayed with manganese
arsenate and a neutral colloidal spreader or with lead arsenate
alone. In the case of apples sprayed with lead arsenate for
the first brood followed by 2 or 3 manganese arsenate and oil
sprays for the second brood, hydrochloric acid was more satis-
factory in the reduction of arsenic if used before the wax
formed to any appreciable extent. The lead was removed to a
lower point with sodium silicate. After wax formed, it was
necessary with the equipment at hand to use a tandem wash of
hydrochloric acid and sodium silicate to successfully reduce
both the lead and the arsenic.

When calcium arsenate was used throughout the season
as a spray combined with oils and spreaders, hydrochloric