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

(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 63 (1995) (p. 325)
CAS No.: 563-47-3
Chem. Abstr. Name: 3-Chloro-2-methyl-1-propene

5. Summary and Evaluation

5.1 Exposure data

3-Chloro-2-methylpropene is produced commercially as a chemical intermediate. It has had limited use as an insecticide and grain fumigant.

5.2 Human carcinogenicity data

No data were available to the Working Group.

5.3 Animal carcinogenicity data

3-Chloro-2-methylpropene containing 5% 1-chloro-2-methylpropene (see monograph, p. 315) was tested for carcinogenicity by oral administration in one experiment in mice and in one experiment in rats. Tumours of the forestomach were induced in mice and rats of each sex.

5.4 Other relevant data

No data were available on the toxicokinetics or toxic effects of 3-chloro-2-methylpropene in humans. It is rapidly absorbed, extensively metabolized and rapidly excreted after oral administration to rats. Most of the excretory products were found in urine; a mercapturic acid was the main metabolite. Considerable amounts were exhaled, some as carbon dioxide.

After repeated oral administrations, 3-chloro-2-methylpropene induced liver necrosis in rats and mice and kidney necrosis in mice; it also induced forestomach hyperplasia in rats.

No data were available on the effects of 3-chloro-2-methylpropene on reproduction in humans or experimental animals.

Micronuclei were not induced in the bone marrow of mice treated in vivo in a single study. 3-Chloro-2-methylpropene induced gene mutation, sister chromatid exchange and chromosomal aberrations in rodent cells in single studies. It was mutagenic to insects and bacteria. The genotoxic effects of this compound cannot be attributed solely to the presence of 1-chloro-2-methylpropene as an impurity.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of 3-chloro-2-methylpropene.

There is limited evidence in experimental animals for the carcinogenicity of 3-chloro-2-methylpropene.

Overall evaluation

3-Chloro-2-methylpropene is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.


Last updated 05/27/1997

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