FAO/PL:1967/M/11/1
WHO/Food Add./68.30
1967 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD
THE MONOGRAPHS
The content of this document is the result of the deliberations of the
Joint Meeting of the FAO Working Party of Experts and the WHO Expert
Committee on Pesticide Residues, which met in Rome, 4 - 11 December,
1967. (FAO/WHO, 1968)
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
WORLD HEALTH ORGANIZATION
Rome, 1968
CARBON DISULFIDE
This pesticide was evaluated for acceptable daily intake by the 1965
Joint Meeting of the FAO Committee on Pesticides in Agriculture and
the WHO Expert Committee on Pesticide Residues (FAO/WHO, 1965). Since
no additional information on the toxicology of this compound has
become available, the following monograph addendum is confined to
evaluation for tolerances and a review of methods of analysis.
EVALUATION FOR TOLERANCES
USE PATTERN
Post-harvest treatments
Carbon disulfide is used as a fumigant to control insects in stored
bulk grain, bagged grain, dry beans and peas, oilcake and potatoes. It
is generally used with carbon tetrachloride (with or without ethylene
dibromide) and in poured on the surface of the grain or in a shallow
dish on top of the grain in silos and bins.
The application rates are variable depending upon the type of
commodity, storage facilities and the temperature.
RESIDUES RESULTING FROM SUPERVISED TRIALS
In wheat, 5.8 ppm carbon disulfide was found 5 days after fumigation
treated at the rate of 275 ml/1000 kg, with a carbon disulfide-carbon
tetrachloride mixture (20 : 80 per cent by vol) and 13.0 ppm after
treatment at the rate of 825 ml/1000 kg with the same mixture (Keppel
and Munsey, 1957). In another experiment the whole wheat, before
cleaning, contained 1.1 and 1.9 ppm carbon disulfide (5 days after
fumigation at the two rates mentioned above) and 0.5 and 0.7
respectively after cleaning and tempering (untreated wheat, before
cleaning contained 0.6 ppm and after cleaning 0.4 ppm). A residue
study in commercially fumigated grain (33 samples of wheat, 13 samples
of corn, 9 of rough rice, 5 of oats and 4 of grain sorghum) showed
maximum residues in wheat, presumably sampled before any turning, of
3.7 ppm of carbon disulfide 5 months after fumigation. Maximum
residues in corn, rough rice, oats and grain sorghum were all lower
than those in wheat (Lynn and Vorhes, 1957).
FATE OF RESIDUES
In storage and processing
Milling
Straight flour, shorts and bran milled from wheat containing 5.8 ppm
carbon disulfide, contained 6.0, 5.9 and 8.3 ppm carbon disulfide
respectively, and from wheat containing 13.0 ppm, 0.7, 3.4 and 1.6 ppm
respectively.
A part of the study mentioned above indicates that in practice the
loss of residues during the cleaning and tempering process before
milling will range upwards to 70 per cent at high initial residue
levels. Only traces of the residue will carry through into the flour.
In flour, shorts, bran and germ (untreated samples contained 0.4, 0.4,
0.4 and 0.3 ppm carbon disulfide respectively), milled from wheat
containing 1.1 ppm residues of 0.5, 0.5, 0.5 and 0.5 ppm respectively
wore found, and from wheat containing 1.9 ppm, 0.5, 0.4, 0.5 and 0.4
ppm respectively (Lynn and Vorhes, 1957).
Baking
Carbon disulfide added at the rate of 10.6 and 7.0 ppm to commercial
bakers' flour and bread bases respectively, approximately 10 times the
maximum levels found in flour after normal fumigation, resulted in
residues in the baked bread of 0.5 ppm (Munsey et al., 1957).
Cooking
Quick-cooking rolled oats, treated with 10.4 ppm carbon disulfide,
after cooking for one minute, resulted in average residues of 1.2 ppm,
thus loss in cooking was 88 per cent. It is unlikely that any
measurable amount of carbon disulfide would be left in cooked
commercial rolled oats which had hem treated at normal dosages (Munsey
et al., 1957).
Comments
From the available data it appears that initial residues are fairly
high and that these residues decrease up to 70 per cent during
cleaning and processing. During baking and cooking much of the
remaining residue disappears.
METHODS OF RESIDUE ANALYSIS
Martens and Nangniot (1963) refer to a polarographic method originally
developed by Zuman. The method is suitable for determination of carbon
disulfide residues in foodstuffs up to a concentration of 2 × 10-4M.
Berck developed a gas chromatographic method suitable for
determination of carbon disulfide alone and a multidetection method
for microgram amounts of 34 fumigant gases (Berck, 1965).
Bielorai and Alumot (1966) developed an electron-capture gas
chromatographic method for determination of residual fumigants in
cereal grains.
NATIONAL TOLERANCES
Country Tolerance, ppm Crop
Bulgaria 0 ppm Cereals
Brazil exempt Cereals
India exempt Cereals
Netherlands 0 ppm Grains
U.S.A. (established) exempt Barley, oats, corn
popcorn, rice, rye,
sorghum (milo), wheat.
RECOMMENDATIONS FOR TOLERANCES
None recommended because of lack of recommendation for an acceptable
daily intake (FAO/WHO, 1965).
FURTHER WORK
Further work required before acceptable daily intakes and tolerances
can be recommended.
It the use of carbon disulfide for the fumigation of certain types of
food proved to be essential, then research would have to be carried
out :
1. on the nature and quantity of the residues present in the treated
food.
2. on the long-term effects in at least two animal species of carbon
disulfide and the products to which it may give rise by reaction
with the protein constituents of food.
REFERENCES PERTINENT TO EVALUATION FOR TOLERANCES
Berck, B. (1965) Determination of fumigant gases by gas
chromatography. J. Agr. Food Chem. 13: 373-377.
Bielorai, R., Alumot, E. (1966) Determination of residues of a
fumigant nature in cereal grain by electron-capture gas
chromatography. Jour. Agr. Food Chem. 14: 622-625.
FAO/WHO. (1965) Evaluation of the hazards to consumers resulting from
the use of fumigants in the protection of food. FAO Mtg. Rpt.
PL/1964/10/2; WHO/Food Add./28.65.
Keppell, G.E., Munsey, V.E. (1957) A second adaptation of Lowen's
dithiocarbamate method. Jour. Assoc. Off. Agr. Chem. 40 : 171-174.
Lynn, G.E., Vorhes, F.A. (1957) Symposium: Residues in food and foods
resulting from fumigation of grains with the commoner liquid
formulations of carbon disulfide, carbon tetrachloride, ethylene
dichloride and ethylene dibromide. Jour. Assoc. Off. Agr. Chem. 40:
163-209.
Martens, P.H., Nangniot, P. (1963) La détermination de résidus
d'insecticides et de fongicides par la méthode polarographique.
Residue Rev. 2: 26-50.
Munsey, V.E., Mills, P.A., Klein, A.K. (1957) Effect of cooking on
fumigant residues. Jour. Assoc. Off. Agr. Chem. 40: 201-202.