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

1-NAPHTHYLTHIOUREA (ANTU)

VOL.: 30 (1983) (p. 347)

5. Summary of Data Reported and Evaluation

5.1 Experimental data

1-Naphthylthiourea was tested for carcinogenicity in mice and rats by administration in the diet. The studies were considered to be inadequate for evaluation.

No data were available to evaluate the teratogenicity of 1-naphthylthiourea to experimental animals.

1-Naphthylthiourea was mutagenic to Salmonella typhimurium in the presence of an exogenous metabolic activation system. It induced a transformed phenotype in Syrian hamster embryo cells in vitro. There is limited evidence that 1-naphthylthiourea is mutagenic in cellular systems. No data were available to evaluate its mutagenicity to mammals.

5.2 Human data

1-Naphthylthiourea was introduced in 1946. Its production, formulation and use as a rodenticide 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 1-naphthylthiourea in humans.

No case report or epidemiological study of the carcinogenicity of 1-naphthylthiourea was available to the Working Group.

5.3 Evaluation

The available data were inadequate to evaluate the carcinogenicity of 1-naphthylthiourea to experimental animals. No data on humans were available.

The available data are insufficient to evaluate the carcinogenicity of 1-naphthylthiourea to humans.

N.B. - Subsequent to the meeting, the Working Group became aware of a study by Davies et al. (1982) in which 12 cases of urothelial tumour were reported among rodent operatives in England who used 1-naphthylthiourea which contained up to 0.2% 2-naphthylamine.

Subsequent evaluation: Suppl. 7 (1987)


Last updated: 16 April 1998






















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