For definition of Groups, see Preamble Evaluation.
VOL.: 60 (1994) (p. 373)
Chem. Abstr. Name: Ethenylmethylbenzene
Chem. Abstr. Name: 1-Ethenyl-2-methylbenzene
Chem. Abstr. Name: 1-Ethenyl-3-methylbenzene
Chem. Abstr. Name: 1-Ethenyl-4-methylbenzene
Vinyl toluene has been produced since the 1940s, as a mixture mainly of meta and para isomers, by dehydrogenation of meta- and para-ethyl toluene. It is used as a reactive monomer in the production of polymers and coatings. Few data are available on levels of occupational or environmental exposures to vinyl toluene.
No data were available to the Working Group.
Vinyl toluene (predominantly para isomer) was tested for carcinogenicity in one experiment in mice and one experiment in rats by intragastric intubation. The mixed isomers were tested in one experiment in mice and one experiment in rats exposed by inhalation. No increase in the incidence of tumours was observed in any of the experiments.
Vinyl toluene is absorbed in rats exposed by inhalation; its neurotoxicity indicates that it is distributed to the brain in both man and rat. The vinyl moiety is first metabolized to form an epoxide, which is either conjugated with glutathione or further oxidized to a number of products, including carboxylic acids, which are conjugated with glycine. The methyl group can also be oxidized to a carboxylic acid and subsequently conjugated with glycine. Saturation of metabolic pathways in rats commences at a dose of 250 mg/kg bw.
No data were available on the genetic and related effects of vinyl toluene in humans.
Vinyl toluene induces sister chromatid exchange and chromosomal aberrations in cultured human lymphocytes and micronuclei in mouse bone-marrow cells in vivo.
There is inadequate evidence in humans for the carcinogenicity of vinyl toluene.
There is evidence suggesting lack of carcinogenicity of vinyl toluene in experimental animals.
Vinyl toluene is not classifiable as to its carcinogenicity to humans (Group 3).
For definition of the italicized terms, see Preamble Evaluation.
See Also: Toxicological Abbreviations