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


VOL.: 20 (1979) (p. 327)

CAS No.: 8001-35-2

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Toxaphene (polychlorinated camphenes) was tested in one experiment in mice and in one in rats by oral administration: a dose-related increase in the incidence of hepatocellular carcinomas was observed in male and female mice, and an increased incidence of thyroid tumours was observed in male and female rats.

Toxaphene is mutagenic in Salmonella typhimurium; it did not induce dominant lethals in mice.

5.2 Human data

No epidemiological studies relating specifically to the carcinogenicity of toxaphene were available to the Working Group.

Two cases of acute aplastic anaemia associated with dermal exposure to toxaphene:lindane mixtures have been reported, one terminating in death due to acute myelomonocytic leukaemia. The only epidemiological study that related to possible carcinogenic effects of toxaphene in humans has weaknesses which prevented the Working Group from drawing any conclusion specific to toxaphene.

An increased frequency of chromosomal aberrations has been observed in the lymphocytes of workers exposed to toxaphene.

The extensive production and the widespread use of toxaphene, together with the persistent nature of the compound, indicate that human exposure occurs. This is confirmed by many reports of its occurrence in the general environment.

5.3 Evaluation

There is sufficient evidence that toxaphene is carcinogenic in mice and rats. In the absence of adequate data in humans, it is reasonable, for practical purposes, to regard toxaphene as if it presented a carcinogenic risk to humans.

Subsequent evaluation: Suppl. 7 (1987) (p. 72: Group 2B); Vol. 79 (2001) (p. 569)

For definition of terms, see Preamble Evaluation.


Last updated: 31 March 1998

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