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

(Group 2B)

For definition of Groups, see Preamble Evaluation.

VOL.: 73 (1999) (p. 295)

CAS No.: 67-72-1
Chem. Abstr. Name: Hexachloroethane

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Exposure to hexachloroethane may occur during its production and use in metal refining, in fire suppression and in other minor uses.

5.2 Human carcinogenicity data

One cohort study of workers at aluminium foundries and aluminium smelters in Sweden showed no significant association between exposure to hexachloroethane and cancer incidence.

5.3 Animal carcinogenicity data

Hexachloroethane was tested in one experiment in mice and two experiments in rats by oral administration. It produced liver tumours in mice of each sex. In rats, it produced a statistically significantly increased incidence of renal tubular tumours in males in one study and a marginal increase in the incidence of renal tubular tumours in another study, also only in males. In a two-stage liver initiation–promotion assay in rats, hexachloroethane showed promoting but no initiating activity.

5.4 Other relevant data

No data were available to the Working Group on the absorption, distribution, metabolism or excretion of hexachloroethane in humans. It is absorbed in rats after oral administration, is concentrated in kidney and fat and is excreted by apparent first-order kinetics.

In humans, exposure by inhalation to hexachloroethane (10–20 mg/m3) produced mild irritation of the skin and mucous membrane. Inhalation produced respiratory irritation in rodents.

After short-term exposure, hexachloroethane caused renal toxicity in male rats and hepatocellular necrosis in both male and female rats.

The data on reproductive toxicity were inadequate for evaluation.

No data were available on the genetic and related effects of hexachloroethane in humans. Hexachloroethane was found to bind to DNA in mouse liver after intraperitoneal injection; no other data were available on its genetic effects in experimental systems in vivo. It induced sister chromatid exchange in one study but did not induce chromosomal damage in mammalian cells in vitro. It induced gene mutation in Drosophila and yeast but was not mutagenic to bacteria.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of hexachloroethane.

There is sufficient evidence in experimental animals for the carcinogenicity of hexachloroethane.

Overall evaluation

Hexachloroethane is possibly carcinogenic to humans (Group 2B).

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluations: Vol. 20 (1999); Suppl. 7 (1987) (p. 64)

Last updated: 30 September 1999

    See Also:
       Toxicological Abbreviations
       Hexachloroethane (ICSC)
       Hexachloroethane  (IARC Summary & Evaluation, Volume 20, 1979)