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


VOL.: 16 (1978) (p. 349)

5. Summary of Data Reported and Evaluation

5.1 Animal data

The data available to the Working Group concerning ortho-toluidine was from experiments that have been insufficiently described. Although tumours have been reported at various sites after administration of the compound by various routes, the inadequacy of reporting does not allow an evaluation of the carcinogenicity of this compound to be made.

5.2 Human data

The epidemiological studies available to the Working Group dealt with workers who had mixed exposures. The results of one study in Germany were equivocal. A second, in Switzerland, had negative results and was inadequate in terms of persons-years exposure. A third, probably representing a large proportion of all workers in the UK who were exposed to ortho-toluidine during the production process, demonstrated one observed case versus 0.52 expected. A fourth, in the USSR, appeared to involve occupational exposure specifically to toluidines; it was suggestive of a carcinogenic effect, but information was incomplete.

These findings, taken together, did not allow the Working Group to draw any firm conclusion about the carcinogenicity of ortho-toluidine to humans.

Subsequent evaluations: Vol. 27 (1982); Suppl. 7 (1987); Vol. 77 (2000)

Last updated: 26 March 1998

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