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

(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 52 (1991) (p. 337)

CAS No.: 79-00-5

5. Summary of Data Reported and Evaluation

5.1 Exposure data

1,1,2-Trichloroethane is used as an intermediate in the production of vinylidene chloride and, to a lesser extent, as a special-purpose industrial solvent and as a chemical intermediate in other processes. It has been detected in drinking-water as well as in untreated groundwater and surface water in some locations; it may occur mainly as a result of industrial emissions.

5.2 Experimental carcinogenicity data

1,1,2-Trichloroethane was tested for carcinogenicity in a two-year study in male and female B6C3F1 mice and Osborne-Mendel rats by oral administration and in Sprague-Dawley rats by subcutaneous injection. In the studies by oral administration, 1,1,2-trichloroethane produced hepatocellular neoplasms and adrenal phaeochromocytomas in mice of each sex but did not significantly increase the proportion of rats with neoplasms at any site relative to untreated controls. In the study in rats by subcutaneous injection, 1,1,2-trichloroethane did not increase the incidence of neoplasms.

In a screening assay for g-glutamyltranspeptidase-positive foci in the liver of male Osborne-Mendel rats, 1,1,2-trichloroethane did not increase the number of foci in the liver in the initiation protocol (single injection), but the number was increased in the promotion protocol (repeated injections), with or without initiation by N-nitrosodiethylamine.

5.3 Human carcinogenicity data

No data were available to the Working Group.

5.4 Other relevant data

1,1,2-Trichloroethane was not mutagenic to bacteria. In single studies, it induced chromosomal malsegregation in a fungus and transformation in cultured mammalian cells. S-Phase induction, but not unscheduled DNA synthesis, was observed in mice after treatment in vivo.

5.5 Evaluation

There is limited evidence for the carcinogenicity of 1,1,2-trichloroethane in experimental animals.

No data were available from studies in humans on the carcinogenicity of 1,1,2-trichloroethane.

Overall evaluation

1,1,2-Trichloroethane is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.


Last updated: 17 November 1997

    See Also:
       Toxicological Abbreviations
       Trichloroethane, 1,1,2- (IARC Summary & Evaluation, Volume 71, 1999)