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 ETHYLENE DICHLORIDE This pesticide was evaluated 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 the previous publication, the available information pertinent to evaluations for tolerances has been restudied and is summarized and discussed in the following monograph addendum. EVALUATION FOR TOLERANCES USE PATTERN Pre-harvest treatments Ethylene dichloride, formulated with carbon tetrachloride, is sometimes used on the trunks and lower branches of fruit trees to control the peach tree borer. It is not used on any growing, edible part of a tree. Therefore, no ethylene dichloride residues result in foods from any known pre-harvest use. Post-harvest treatments A 3:1 ethylene dichloride-carbon tetrachloride mixture is commonly used as a fumigant for grain, pulses, and animal feeds. It is applied to these commodities while they are in bulk storage bins or under gasproof covers. The mixture is used at the rate of 2 to 6.5 gal/1,000 bu (0.2 to 0.7 l/m3), depending on the product being treated and the type of enclosure. Other uses It is occasionally used for fumigating household articles such as clothing, rugs, upholstery, etc. RESIDUES RESULTING FROM SUPERVISED TRIALS Winteringham (1944a) found that sorption of ethylene dichloride by flour reached equilibrium within 24 hours, but sorption by whole wheat still continued after 1 week. In another study (1944b), he concluded that the retention of ethylene dichloride by wheat is physical and that there in no chemical decomposition of the fumigant within the product. Maximum residues on wheat obtained from fumigation with ethylene dichloride (35 per cent) in combination with carbon tetrachloride (60 per cent) and ethylene dibromide (5 per cent) at the recommended dosage (2 gal/1,000 bu) (0.2 l/m3) and at triple the dosage were 55 and 140 ppm of ethylene dichloride, respectively (Conroy, Walkden, and Farrell, 1957). Wheat treated with a mixture of carbon tetrachloride, ethylene dichloride, and ethylene dibromide (60:35:5 per cent by volume) at the normal dosage had 76 ppm of organic chloride in the wheat and 17, 22, and 58 ppm of ethylene dichloride in the flour, shorts, and bran, respectively (Munsey, 1957). RESIDUES IN FOOD MOVING IN COMMERCE Analyses conducted by The Netherlands during 1964-1965 period (CCPR, 1966) showed that 4 out of 227 lots of cereal sampled, or 1.6 per cent of those imported, had ethylene dichloride present. The origin of the cereals with ethylene dichloride residues and the amounts found were: United States 5 ppm Argentina 1.4 ppm 70 ppm 70 ppm FATE OF RESIDUES In storage and processing After wheat containing 140 ppm of ethylene dichloride was cleaned and tempered, the residue fell to 41 ppm. Wheat with 34.6 ppm of ethylene dichloride had 17.8 ppm after cleaning and tempering, and residues in the fractions after milling were 3 ppm in the flour, 3.5 ppm in the shorts, 22.8 ppm in the bran, and 12.0 ppm in the germ (Conroy, Walkden, and Farrell, 1957). Five bins of wheat fumigated with a carbon tetrachloride-ethylene dichloride mixture had 418 ppm of ethylene dichloride, 24 hours after fumigation, 325 ppm after the first turning (transfer to another bin), and 263 ppm after the third turning (Stenger and Mapes, 1957). Ethylene dichloride was added to flour at 6.1 and 40 ppm, the flour made into bread dough, and the dough then baked. The bread made from the two batches had less than 2 ppm of ethylene dichloride. Oats with 61.6 ppm of ethylene dichloride had an average of 31.4 ppm after cooking (1 min) or a loss of 49 per cent (Munsey, Mills, and Klein, 1957). When ethylene dichloride at levels up to 1,000 ppm was added to grain and was fed to cows, an average of less than 0.25 ppm was found in the milk. There appeared to be no direct correlation between the amounts of ethylene dichloride added to the grain and that found in the milk (Sykes and Klein, 1957) When 140 pounds (63.5 kg) of 85-per cent extracted wheat flour was fumigated for 48 hours at 25°C with 300 g of ethylene dichloride (11.1 lb/ton), samples from the center of the bag had 1,030 ppm, 350 ppm, and 46 ppm after airing 1 hour, 2 days, and 7 days, respectively (Pest Infestation Laboratory, 1943). METHODS OF RESIDUE ANALYSIS Ethylene dichloride residues have been determined by the combined methods of Ramsey (1957) which measures the carbon tetrachloride and of Conroy, Munsey, and Ramsey (1957) which measures the total organic halides. The amount of ethylene dichloride is calculated by subtracting the amount of carbon tetrachloride from the total inorganic halides. The sensitivity is 0.5 ppm. An electron-capture gas chromatographic method for detecting certain chlorinated residues in the ppb range has been described by Bielorai and Alumot (1966). This method may be adapted for ethylene dichloride residue analysis. NATIONAL TOLERANCES Country Tolerances Crop Canada Exempt Grain United States Exempt1/ Grain 1/According to U.S. Food and Drug laws, ethylene dichloride is exempt from requirement of a residue tolerance because when used as a fumigant for grain under currently prevailing practices it does not appear to involve any hazard to public health. RECOMMENDATIONS FOR TOLERANCES Cereals fumigated with ethylene dichloride according to good agricultural practices may contain high levels of the fumigant for a relatively long time. Aeration, aging, and processing will remove most of the ethylene dichloride but very small amounts may persist in the food. Since no reaction products or metabolites of ethylene dichloride have been found in grain, (IUPAC, 1967), the concern is over the amount of the ethylene dichloride per se present in the food when it reaches the consumer. No suitable analytical method is available for the specific determination of this fumigant. Furthermore no acceptable daily intake (ADI) could be estimated at this time with the available toxicological data. Under the above conditions, no tolerances were recommended for ethylene dichloride. FURTHER WORK Further work required before acceptable daily intakes and tolerances can be recommended In addition to that specified in the previous publication (FAO/WHO, 1965) further data is required on: Extent of use as a fumigant for raw and processed foods. Residue levels in various food resulting from good agricultural practices and the effects of aerating, aging, processing, and cooking in reducing residues of ethylene dichloride. Development of a specific method for detecting ethylene dichloride with a sensitivity of about .001 ppm. Residue levels of ethylene dichloride in various types of food while in trade channels. REFERENCES PERTINENT TO EVALUATION FOR TOLERANCES Bielorai, R. and Alumot, E. (1966) Determination of residues of fumigant mixture in cereal grain by electron-capture gas chromatography. J. Agric. Fd. Chem., 14(6) : 622-625. CCPR. (1966) Codex Committee on Pesticide Residues. Residues of insecticides in cereals, imported in the Netherlands, 1964/65, Second Report. Paper prepared by the Ministry of Social Affairs and Public Health, Ministry of Agriculture. CCPR 66-17. Conroy, H.W., Munsey, V.E., and Ramsey, L.L. (1957) Residues foods and foods resulting from fumigation of grains with the commoner liquid formulations of carbon disulfide, carbon tetrachloride, ethylene dichloride, and ethylene dibromide. 2. Ethanolamine-sodium reduction procedure. J. Ass. Off. Agric. Chem., 40 (1) 9 185-189. Conroy, H.W., Walkden, H.H., and Farrell, E. (1957) The fumigation, milling, and sampling of wheat and its milled products. B. Manhattan studies. J. Ass. Off. Agric. Chem., 40 (1) : 166-168, 192-195. FAO/WHO. (1965) Evaluation of the hazards to consumers resulting from the use of fumigants in the protection of food. FAO Mtg. Rept. No. PL/1965/10/2; WHO/Food Add./28.65. IUPAC. (1967) International Union of Pure and Applied Chemistry. Proceedings of the Commission on Terminal Residues and the Commission on Residue Analysis. Vienna, August, 1967. Munsey, V.E. (1957) The fumigation, milling and sampling of wheat and its milled products. J. Ass. Off. Agric. Chem., 40(1) : 165, 192. Munsey, V.E., Mills, P.A., and Klein A.K. (1957) Effects of cooking on fumigated residues. J. Ass. Off. Agric. Chem., 40(1) : 201-202. Pest Infestation Laboratory. (1943) Pest Infestation Research Report : 87. Slough, England. Ramsay, L.L. (1957) Residues in foods and feeds resulting from fumigation of grains with the commoner liquid formulations of carbon disulfide, carbon tetrachloride, ethylene dichloride, and ethylene dibromide. B. Colorimetric determination of carbon tetrachloride in fumigated cereal products. J. Ass. Off. Agric. Chem., 40(1) : 175-180. Stenger, V.A. and Mapes, D.A. (1957) Effect of baking on ethylene dibromide and total bromide residues. J. Ass. Off. Agric. Chem., 40(1): 196-200. Sykes, J.F. and Klein, A.K. (1957) Chloro-organic residues in milk of cows orally administered ethylene dichloride. J. Ass. Off. Agric. Chem., 40(1) : 203-206. Winteringham, F.P.W. (1944a) The sorption of ethylene dichloride by wheat products. J. Soc. Chem. Ind., 63 : 144-150. Winteringham, F.P.W. (1944b) The sorption of ethylene dichloride by wheat products. J. Soc. Chem. Ind., 63 : 359-363.
See Also: Toxicological Abbreviations Ethylene dichloride (FAO Meeting Report PL/1965/10/2)