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 PROPHAM Chemical name Isopropyl N-phenylcarbamate; N-phenyl-isopropylcarbamate; isopropyl-carbanilate. Synonym IPC Empirical formula C10H13O2N Structural formulaBIOLOGICAL DATA Acute toxicity Animal Route LD50 mg/kg References body-weight Mouse Oral approx. 3000 van Esch et al., 1958 Mouse Intraperitoneal approx. 1000 van Esch et al., 1958 Rat Oral 9000 van Esch et al., 1958 Rat Intraperitoneal 600 van Esch et al., 1958 Short-term studies Mouse. Groups of 30 mice, 15 females and 15 males were given the following oral doses of propham: 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. Propham was used as initiator and croton oil was painted on the skin as a promoter. Although in some of the original groups skin papillomas developed following applications of croton oil in mice fed propham, this result could not be confirmed in a number of subsequent experiments carried on in the same institution. No lung tumours were found in these experiments. Positive controls given ethylurethane in the place of propham developed both skin papillomas and lung adenomas (van Esch et al., 1958; van Esch, 1965). Rat. Ten rats were fed for one month a diet containing 10 000 ppm of propham. No differences in weight gain in comparison with the control rats were found (Brown & Gross, 1949). Groups of 4 rats were fed 400, 800 and 1600 ppm for 3 months; the growth rate and reproduction was normal. No gross abnormalities were seen in the lung, liver, intestine or kidneys (Schuurmans Stekhoven et al., 1955). Pig. Groups of 4 pigs were fed 3300 ppm of propham for 19 weeks. No differences in weight gain from the controls were found. At autopsy no gross abnormalities were seen. Liver, kidney and spleen were histologically normal. No changes in the blood picture were observed (van Esch & van Genderen, 1956-57). Long-term studies Mouse. Groups of 30 mice were given 10 000 and 20 000 ppm of propham in their diet for approximately 18 months. The mortality rate was very high, especially in the beginning. Further groups each of 50 mice were given 1000 and 5000 ppm. The mice became emaciated, lost appetite and many of them died unless they were taken off the experimental diet every 2 weeks and placed on normal diet for an equal period. Loss of hair was noticed. At autopsy no benign or malignant tumours were found in the lungs or other organs. Sixty mice were given injections every 2 weeks of a suspension of propham in lanolin into the right femoral muscle; the doses were equivalent to 40 mg/100 g body-weight. The injections were continued for 6 months. The duration of the experiment was 10 months. At the site of injection encapsulated injection material was present without reaction of the surrounding tissue. There was no evidence of any neoplastic reaction (Hueper, 1952). The experiment was repeated in 60 mice, but the injections were given in the right pleural cavity. The duration of the experiment was 18 months. No evidence of tumour formation was present (Hueper, 1952). Rat. Fifteen adult rats were given 20 000 ppm propham in their diet for 18 months. The rats were given alternately the propham diet for 1-2 months and a normal diet for 1-2 weeks; at autopsy no tumours were found. No histopathological changes were seen (Hueper, 1952). Fifteen rats were given monthly injections of a suspension of propham in lanolin into the right femoral muscle in doses equivalent to 40 mg/100 g body-weight. The injections were continued for 6 months. The duration of the experiment was 18 months. At the site of injection, encapsulated injected material was present with inflammatory foam cell reaction around it but no other reaction. The experiments were repeated with 15 rats but the injections were given in the right pleural cavity. The duration of the experiment was 18 months. In these experiments no tumours of any kind were present (Hueper, 1952). Three groups each of 9 rats were given orally approximately 1000 and 1500 ppm propham and 1000 ppm ethylurethane in dry feed. Twelve more animals were added as controls. The first group was fed for 18 months, the other 2 groups for 15 months. After 15 and 18 months no lung tumours were seen (Engelhorn, 1954). Comments on experimental work reported The suspicion that propham 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 a no-effect level. Further work required Biochemical studies. Further long-term feeding studies in the rat and other species. Further work considered desirable Biochemistry of propham and further work on carcinogenicity. REFERENCES Brown, J. H. & Gross, P. (1949) Report of Ind. Hyg. Foundation to Pittsburgh Plate Glass Co. 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. (1956-57) Preliminary reports of the National Institute of Public Health van Esch, G. J., van Genderen, H. & Vink, H. H. (1958) Brit. J. Cancer, 12, 355 Engelhorn, R. (1954) Naunyn-Schmiedeberg's Arch. exp. Path. Pharmak., 223, 177 Hueper, W. C. (1952) Industr. Med. Surg., 21, 71 Schuurmans Stekhoven, J. H., Roskott, L. & Veenhof, M. J. (1955) T. Diergeneesk., 80, 400
See Also: Toxicological Abbreviations Propham (Pesticide residues in food: 1992 evaluations Part II Toxicology) Propham (IARC Summary & Evaluation, Volume 12, 1976)