FAO Meeting Report No. PL/1965/10/1 WHO/Food Add./27.65 EVALUATION OF THE TOXICITY OF PESTICIDE RESIDUES IN FOOD The content of this document is the result of the deliberations of the Joint Meeting of the FAO Committee on Pesticides in Agriculture and the WHO Expert Committee on Pesticide Residues, which met in Rome, 15-22 March 19651 Food and Agriculture Organization of the United Nations World Health Organization 1965 1 Report of the second joint meeting of the FAO Committee on Pesticides in Agriculture and the WHO Expert Committee on Pesticide Residues, FAO Meeting Report No. PL/1965/10; WHO/Food Add./26.65 CHLOROBENZILATE Chemical name ethyl-2-hydroxy-2,2-di(p-chlorophenyl) acetate; ethyl 4,4'-dichlorobenzilate; ethyl 4,4'-dichlorodiphenylglycollate. Empirical formula C16H14O3Cl2 Structural formulaBIOLOGICAL DATA Biochemical aspects Chlorobenzilate appears to undergo extensive hydrolysis in the body to the acid form which is the main excretion product. Acute toxicity Animal Route LD50 mg/kg References body-weight Mouse Oral 729 Horn et al., 1955 (Technical product) Mouse Oral 4 850 Gasser, 1952a; Gasser, 1952b Rat Oral 702 Horn et al., 1955 (Technical product) Rat Oral 3 100 Gasser, 1952a; Gasser, 1952b Rat Oral 735 Horn et al., 1955 (25% xylene emulsion) Short-term studies Rat. Groups of rats, each of 20 males, were fed 40 and 800 ppm of technical chlorobenzilate in the diet for 44 or 48 weeks (Geigy, 1953-55). The rats receiving 40 ppm grew at about the same rate as the controls, but those receiving 800 ppm were markedly retarded as to growth. Several animals receiving 800 ppm exhibited red or swollen eyelids and soft faeces, and one developed diarrhoea. During the test, 2 control rats and 5 rats receiving 800 ppm died, there were no deaths among those receiving 40 ppm. Gross autopsy of all survivors showed no characteristic changes attributable to feeding of the compound. The weights of the liver, kidneys, and testes of rats receiving 40 ppm, when expressed as percentages of body-weight, were significantly greater than those of the controls. The organ weights of rats receiving 800 ppm were not evaluated statistically, though the absolute weights were less than at 40 ppm. Microscopic examination of the main organs revealed no significant histological changes attributable to the administration of the compound, but non-specific histological changes were noted in the pancreas and adrenals of some rats receiving 40 ppm and in the spleen, pancreas and adrenals of the rats receiving 800 ppm (Geigy, 1953-55). Dog. Groups of 2 dogs, one male and one female in each group, were given 12.8 mg and 64.1 mg/kg body-weight per day for 35 weeks. All dogs either maintained their body-weight or made slight weight gains; they showed normal behaviour, had good appetite, and showed no gross signs of toxicity throughout the entire study. Biochemical and haematological results were within normal limits. Gross and microscopic examination of the main organs revealed no significant pathological changes at the end of the 35-week period (Horn et al., 1955). Long-term studies Rat. Groups each of 40 rats (20 males and 20 females) were fed 500 ppm of technical chlorobenzilate for 2 years, and one group of 20 males was fed 50 ppm of the compound for 2 years (Horn et al., 1955). Only the males receiving 500 ppm showed a significantly lower weight gain as compared to the controls. Tissues from the main organs were examined. The histopathological findings could not be attributed to the feeding of chlorobenzilate for 2 years. The organ weights of liver, kidneys and spleen were not significantly different from those of the controls. In the males receiving 50 and 500 ppm there was an increase in the frequency of atrophied testes (Horn et al., 1955). Comments on experimental studies reported and evaluation The maximum no-effect level in the rat appears to be about 50 ppm, but further animal studies are required to confirm this before an evaluation can be made. Further work required Metabolic studies in animals. Additional long-term studies in rats at lower dose-levels and long-term studies in other species. REFERENCES Gasser, R. (1952a) Compte Rendues, IIIe Congrès international de phytopharmacie, Paris, p. 357 Gasser, R. (1952b) Experienta, 8, 65 Geigy Chemical Corp., Yonkers, New York, 1953-55, Unpublished data Horn, J. J., Bruce, R. B. & Paynter, O. E. (1955) J. Agric. Food Chem., 3, 752
See Also: Toxicological Abbreviations Chlorobenzilate (ICSC) Chlorobenzilate (FAO/PL:1968/M/9/1) Chlorobenzilate (WHO Pesticide Residues Series 2) Chlorobenzilate (WHO Pesticide Residues Series 5) Chlorobenzilate (Pesticide residues in food: 1977 evaluations) Chlorobenzilate (Pesticide residues in food: 1980 evaluations) Chlorobenzilate (IARC Summary & Evaluation, Volume 5, 1974) Chlorobenzilate (IARC Summary & Evaluation, Volume 30, 1983)