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 CHLORPROPHAM Chemical names Isopropyl N-(3-chlorophenyl)carbmate; isopropyl chlorocarbanilate Synonyms CIPC Empirical formula C10H12O2N Cl Structural formulaBIOLOGICAL DATA Acute toxicity Animal Route LD50 mg/kg References body-weight Rat Oral 5000-8000 van Esch & van Genderen, 1956; Westrick at al., 1953 Rat Intraperitoneal 700 van Esch & van Genderen, 1956 Rabbit Oral approx. 5000 Westrick et al., 1953 Short-term studies Mouse. Groups each of 30 mice, 15 females and 15 males, were given the following oral doses of chlorpropham : One group, a single dose of 750 mg/kg body-weight; a second group, once a week an oral dose of 750 mg/kg body-weight; and a third group, 1000 ppm in the diet for 6 months. Chlorpropham and also ethylurethane were used as initiators and croton oil was painted on the skin as a promoter. Although in some of the original experiments skin papillomas developed following applications of croton oil in mice fed clorpropham, this result could not be confirmed in a number or subsequent experiments carried on in the same institution. No lung tumours were found in these experiments. Positive controls given ethylurethane in the place of chlorpropham developed both skin papillomas and lung adenomas (van Esch et al., 1958; van Esch, 1965). Rat. Groups of 10 rats were fed diets containing 310, 1250, 5000 and 20 000 ppm of chlorpropham for 90 days. All groups showed an increase in weight and food-intake as compared with the controls. The mean liver weights of the animals receiving 1250, 5000 and 20 000 ppm were significantly higher than those of the controls (no significant changes in kidney weight). No microscopic changes in the liver and the kidney after 90 days were found (Westrick et al., 1953). Dog. Groups of 4 dogs (2 male and 2 female) were given 200, 2000 and 20 000 ppm of chlorpropham in their diet for one year. All animals showed initial weight loss, but only the animals receiving 20 000 ppm failed to surpass the average starting weight for the group during the experimental period; no animals died and there was no apparent morbidity. Lower haemoglobin and haematocrit values were found in the first six-month feeding period on 20 000 ppm but not at the end of the 12-month feeding period. The weights of the liver and spleen relative to body-weight increased at the 20 000 ppm level (Larson et al., 1960). Pig. Pigs, 4 per group, received 3300 ppm of chlorpropham in their diet for 19 weeks. There was no effect on weight gain, and at autopsy no pathological abnormalities were observed. The liver, kidney and spleen were histologically normal. No changes in the blood picture, except a slight decrease in haemoglobin content in the nineteenth week, were present (van Esch & van Genderen, 1956). Long-term studies Rat. Groups each of 50 rats, 25 males and 25 females, were administered 200, 2000 and 20 000 ppm chlorpropham in their diet for 2 years. No abnormalities were observed at concentrations of 200 and 2000 ppm. At 20 000 ppm growth was depressed, the mortality rate of the males was increased, and the haematocrit and haemoglobin values were lowered; increases in liver and spleen weights relative to body-weight were observed. Tumour incidence in the treated animals was not greater than in the control animals (Larson et al., 1960). Comments on experimental work reported The suspicion that chlorpropham could be a co-carcinogen for mice could not be confirmed. In other species experiments purposely designed did not indicate any tumorigenic effect. EVALUATION Not enough toxicological data on animals are available at present to set no-effect levels. Further work required Biochemical studies; long-term feeding studies in other species than the rat. REFERENCES van Esch, G. J. (1965) Personal communication concerning data from the National Institute of Public Health, Utrecht, The Netherlands van Esch, G. J. & van Genderen. H. (1956) Preliminary report of the National Institute of Public Health van Esch, G. J., van Genderen, H. & Vink, H. H. (1958) Brit. J. Cancer, 3, 355 Larson, F. S., Crawford, E. M., Blackwell Smith, R., Hennigar, G. R., Haag, H. B. & Finnegan, J. K. (1960) Toxicol. Appl. Pharmacol., 2, 659 Westrick, M. L., Gross, P. & Schrenk, H. H. (1953) Report from Ind. Hyg. Foundation America to Pittsburgh Plate Glass Company, June/September and September/December
See Also: Toxicological Abbreviations Chlorpropham (ICSC) Chlorpropham (JMPR Evaluations 2000 Part II Toxicological) Chlorpropham (JMPR Evaluations 2005 Part II Toxicological)