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

(Group 2B)

For definition of Groups, see Preamble Evaluation.

VOL.: 60 (1994) (p. 361)
CAS No.: 106-87-6
Chem. Abstr. Name: 3-Oxiranyl-7-oxabicyclo[4.1.0]heptane

5. Summary of Data Reported and Evaluation

5.1 Exposure data

4-Vinylcyclohexene diepoxide is produced by epoxidation of 4-vinylcyclohexene with peroxyacetic acid. It is used as a reactive diluent for other diepoxides and for epoxy resins. No data are available on levels of occupational exposure to 4-vinylcyclohexene diepoxide.

5.2 Human carcinogenicity data

No data were available to the Working Group.

5.3 Animal carcinogenicity data

4-Vinylcyclohexene diepoxide was tested for carcinogenicity by skin application in three studies in mice and in one study in rats. Skin application of 4-vinylcyclohexene diepoxide produced benign and malignant skin tumours in all studies in mice and in the study in rats. In one study in mice, it also increased the incidences of ovarian and lung tumours in females.

5.4 Other relevant data

4-Vinylcyclohexene diepoxide can be absorbed through the skin of rodents. Higher concentrations tend to be found in the ovary rather than in other organs, and virtually all elimination occurs via the urine. Its metabolism involves hydration to a mixture of glycols and conjugation with glutathione.

4-Vinylcyclohexene diepoxide is locally toxic and, when given orally, causes ovarian degeneration in both mice and rats and testicular degeneration in mice, as well as lesser effects in other organs.

No data were available on the genetic and related effects of 4-vinylcyclohexene diepoxide in humans.

4-Vinylcyclohexene diepoxide induced gene mutation, sister chromatid exchange and chromosomal aberrations but not micronuclei in mammalian cells in vitro. It was mutagenic in bacteria and caused gene conversion and mitotic crossing-over in Saccharomyces cerevisiae.

A metabolite of 4-vinylcyclohexene diepoxide, 4-epoxyethylcyclohexane-1,2-diol, was not mutagenic to Salmonella typhimurium.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of 4-vinylcylcohexene diepoxide.

There is sufficient evidence in experimental animals for the carcinogenicity of 4-vinyl-cyclohexene diepoxide.

Overall evaluation

4-Vinylcyclohexene diepoxide is possibly carcinogenic to humans (Group 2B).

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluation: Suppl. 7 (1987) (p. 63)


Last updated 08/26/1997

    See Also:
       Toxicological Abbreviations