International Agency for Research on Cancer (IARC) - Summaries & Evaluations


VOL.: 30 (1983) (p. 295)

CAS No.: l33-06-2
Chem. Abstr. Name: 1H-Isoindole-l,3(2H)-dione, 3a,4,7,7a-tetrahydro-2-[(trichloromethyl)thio]-

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Captan was tested for carcinogenicity in mice and rats by administration in the diet. It was carcinogenic to one strain of mice, inducing duodenal tumours (adenocarcinoma and adenomatous polyp). No evidence of carcinogenicity was found in rats.

Captan has shown little, if any, embryotoxic or teratogenic potential in mice or rats at maternally tolerated doses. Results obtained in tests with rabbits and hamsters were considered inconclusive.

Captan was mutagenic to bacteria and yeast. Both positive and negative results were obtained in the host-mediated assay in mice. Weak or negative effects were observed in Drosophila melanogaster. Captan induced chromosomal aberrations, sister chromatid exchange and mutations at several loci, but not unscheduled DNA synthesis, in cultured mammalian cells. No increase in micronucleated erythrocytes or chromosomal aberrations was detected in treated mice or rats; positive results obtained in dominant lethal tests in mice and rats were not confirmed by other studies. Thus, there is sufficient evidence to establish the mutagenicity of captan in cellular systems, but the data were insufficient to establish its mutagenicity in mammals.

5.2 Human data

Captan was introduced commercially in 1951. Its production, formulation and use as a fungicide in agricultural and industrial applications and in cosmetics are potential sources of exposure, both of workers and of the general population.

No data were available to evaluate the teratogenic or chromosomal effects of captan in humans.

No case report or epidemiological study of the carcinogenicity of captan alone was available to the Working Group. (See, however, the section 'Cancer Epidemiology of Pesticide Manufacturers, Formulators and Users', in this volume.)

5.3 Evaluation

Results of the experiments in mice provide limited evidence that captan is carcinogenic to experimental animals. No data on humans were available.

The available data are insufficient to evaluate the carcinogenicity of captan to humans.

For definition of the italicized terms, see Preamble Evaluation.

Subsequent evaluation: Suppl. 7 (1987) (p. 59: Group 3)


Last updated: 16 April 1998

    See Also:
       Toxicological Abbreviations
       Captan (HSG 50, 1990)
       Captan (ICSC)
       Captan (PIM 098)
       Captan (FAO/PL:1969/M/17/1)
       Captan (WHO Pesticide Residues Series 3)
       Captan (WHO Pesticide Residues Series 4)
       Captan (Pesticide residues in food: 1977 evaluations)
       Captan (Pesticide residues in food: 1978 evaluations)
       Captan (Pesticide residues in food: 1980 evaluations)
       Captan (Pesticide residues in food: 1982 evaluations)
       Captan (Pesticide residues in food: 1984 evaluations)
       Captan (Pesticide residues in food: 1984 evaluations)
       Captan (Pesticide residues in food: 1990 evaluations Toxicology)
       Captan (Pesticide residues in food: 1995 evaluations Part II Toxicological & Environmental)