AGP:1970/M/12/1 WHO/FOOD ADD/71.42 1970 EVALUATIONS OF SOME PESTICIDE RESIDUES IN FOOD THE MONOGRAPHS Issued jointly by FAO and WHO 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 Group on Pesticide Residues, which met in Rome, 9-16 November, 1970. FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS WORLD HEALTH ORGANIZATION Rome, 1971 CARBARYL Explanation This compound was evaluated by Joint Meetings in 1966, 1967, 1968 and 1969 (FAO/WHO, 1967b, 1968b, 1969b and 1970b). A temporary acceptable daily intake for man of 0.01 mg/kg was proposed in 1969, to be reviewed in 1973. In 1969, temporary tolerances proposed in 1967 and others added in 1968 were revised and extended, but that proposed in 1968 for whole milk was withdrawn. Further information required by 30 June 1970 included: (a) results from total diet studies, (b) data on residue levels in whole milk, (c) data on the disappearance of residues during storage and processing of cocoa beans and derived products and of cereals into cereal products, More sensitive methods of analysis, especially for total diet studies, were considered desirable. RESIDUES IN FOOD AND THEIR EVALUATION Results of studies on dietary intake in the U.S.A. have been summarized by Duggan and Lipscomb (1969). The percentage of total diet samples containing carbaryl and the daily intake per kg bodyweight were 7.4 and 0.15 mg in 1965, 2.7 and 0.026 mg in 1966, 1.1 and <0.01 mg in 1967, and were below the limits of measurement in 1968. These authors concluded that, for diets in the U.S.A., "Carbamate chemicals and carbaryl do not occur at sufficiently high levels or frequencies to be considered as contributors to the daily intake of pesticide chemicals." No new information has been received concerning residue levels in milk nor on the fate of residues in storage or processing of cocoa beans or cereals; items b, c and d of the information requested therefore remain unanswered. Evidence on the effect of simple washing on residue levels on cabbage and eggplant have been published from India (Mann and Chopra, 1969). Samples were taken at intervals up to seven days after the fourth application by spraying of carbaryl in nine-week periods, and half of these samples on each occasion were washed before analysis. The spraying rates, intervals between spraying and harvesting, and the residue levels on unwashed and washed samples are given in Table I. The temporary tolerance of 5 ppm in poultry set by the 1969 Joint Meeting on a whole meat basis, including skin, was referred back by the 5th Meeting of the Codex Committee on Pesticide Residues. Further data have been provided that show that the distribution of residues varies considerably with the method of application of carbaryl. The method of analysis was colorimetric and determined carbaryl and 1-naphthol at 0.1 and. 0.2 ppm, respectively. Residues of 1-naphthol never exceeded 10% of those of carbaryl. Even when carbaryl was applied at frequent intervals and rates above those recommended, TABLE I Carbaryl residues (ppm) present after spraying1 Picking 0.1% (0.62 kg/ha) 0.2% (1.24 kg/ha) 0.4% (2.48 kg/ha) interval (days) unwashed washed unwashed washed unwashed washed Cabbage 0 14.80 0.97 23.83 1.34 33.86 1.25 1 9.00 2.08 13.33 3.81 18.57 5.61 3 5.72 2.77 8.15 3.41 10.41 5.05 5 3.83 2.88 5.86 2.72 6.99 3.80 7 2.50 1.44 3.94 2.17 5.13 2.94 Eggplant 1 8.33 - 12.22 - 16.86 - 3 5.29 1.98 7.30 3.14 9.85 4.70 5 3.58 1.80 5.08 2.55 6.42 3.38 7 3.05 1.30 4.31 1.99 5.40 2.80 1 A comparison of the rates of dissipation for washed and unwashed cabbage shows that washing removes the initial deposit readily, but that carbaryl penetrates into the plant during the first day or two to a considerable extent. Comparable deposits and penetration occur on the eggplant. residues after seven days in tissues other than the skin did not exceed the limit of measurement. Residues on the skin did not exceed 3 ppm. Since the skin provides about 9% of the total edible tissues, a temporary tolerance of 0.5 ppm for the edible parts of prepared birds should be sufficient; the previously recommended figure of 5 ppm thereby applies only to the skin of poultry. METHODS OF RESIDUE ANALYSIS Two methods using GLC with electron capture have recently been described. In Cohen et al. (1970) recoveries from spiked samples of lettuce and peas were 82% and 87% respectively, from apples, 94% and the level of detection in plant material was reported to be 0.1 ppm. Tilden and Van Middelem (1970) claim a limit of 0.2 ppm, but were unable to avoid a high reagent blank. These methods seem suitable for regulatory purposes. APPRAISAL Further information has been received concerning the levels of carbaryl present in various organs and tissues of laying hens and turkey poults killed seven days after treatment by various methods of external application. This indicates that the temporary tolerance of 5 ppm for poultry, recommended at the Joint Meeting in December 1969, should be adequate for poultry skin, but that the tolerance for prepared birds, i.e. the total edible portion, including the skin, could be reduced to 0.5 ppm. Studies on total dietary intake from the U.S.A. over the period 1965-1968 showed that intake was rapidly decreasing and was below the limit of determination in the final year. Harvest residue data on cabbage and eggplant indicate that the recommended tolerance of 5 ppm should be retained. Two analytical methods using G.L.C. with electron capture detection have been described, one reports the lower level of detection to be 0.1 ppm. FURTHER WORK OR INFORMATION REQUIRED (before tolerances can be set for whole milk and milk products) Further data on residue levels. REFERENCES Cohen, I.C., Norcup, J, Ruzicka, J.H.A., and Wheals, B.B. (1970) An electron-capture gas chromatographic method for the determination of some carbamate insecticides as 2,4-dinitrophenyl derivatives of their phenol moieties. J. Chromatog., 49: 215-221. Duggan, R.E., and Lipscomb, G.Q. (1969) Dietary intake of pesticide chemicals in the United States (II), June 1966 - April 1968. Pestic. Monit. J., 2 (4): 153-162. Mann, G.S., and Chopra, S.L. (1969) Residues of carbaryl on crops. Pestic. Monit. J., 2 (4): 163-166. Tilden, R.L. and Van Middelem, G.H. (1970) Determination of carbaryl as an amide derivative by electron-capture gas chromatography. J. Agr. Food Chem., 18: 154-158.
See Also: Toxicological Abbreviations Carbaryl (EHC 153, 1994) Carbaryl (HSG 78, 1993) Carbaryl (ICSC) Carbaryl (PIM 147) Carbaryl (FAO Meeting Report PL/1965/10/1) Carbaryl (FAO/PL:CP/15) Carbaryl (FAO/PL:1967/M/11/1) Carbaryl (FAO/PL:1968/M/9/1) Carbaryl (FAO/PL:1969/M/17/1) Carbaryl (WHO Pesticide Residues Series 3) Carbaryl (WHO Pesticide Residues Series 5) Carbaryl (Pesticide residues in food: 1976 evaluations) Carbaryl (Pesticide residues in food: 1977 evaluations) Carbaryl (Pesticide residues in food: 1979 evaluations) Carbaryl (Pesticide residues in food: 1984 evaluations) Carbaryl (Pesticide residues in food: 1996 evaluations Part II Toxicological) Carbaryl (JMPR Evaluations 2001 Part II Toxicological) Carbaryl (IARC Summary & Evaluation, Volume 12, 1976)