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

(Group 2B)

For definition of Groups, see Preamble Evaluation.

VOL.: 48 (1990) (p. 45)

CAS No.: 115-28-6
Chem. Abstr. Name: Bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid, 1,4,5,6,7,7,-hexachloro-

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Chlorendic acid is used primarily as a chemical intermediate in the manufacture of unsaturated polyester resins that have applications in electrical systems, panelling, engineering plastics and paints. It is also used in the textile industry for flame-retardant treatment of wool. No data on occupational exposure levels were available.

5.2 Experimental carcinogenicity data

Chlorendic acid was tested for carcinogenicity by oral administration in one strain of mice and one strain of rats. It produced hepatocellular adenomas and carcinomas in male mice and an increase in the incidence of alveolar/bronchiolar tumours and follicular-cell adenomas of the thyroid gland in female mice. In rats, it induced hepatocellular adenomas in animals of each sex and hepatocellular carcinomas in females; in male rats, it induced an increase in the incidence of alveolar/bronchiolar adenomas and of acinar-cell adenomas of the pancreas.

5.3 Human carcinogenicity data

No data were available to the Working Group.

5.4 Other relevant data

Hepatocytomegaly was observed in mice and rats fed chlorendic acid for 13 weeks.

In single studies, chlorendic acid induced mutations in mammalian cells in culture but was not mutagenic to bacteria in the presence or absence of an exogenous metabolic system.

5.5 Evaluation

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

No data were available from studies in humans on the carcinogenicity of chlorendic acid.

Overall evaluation

Chlorendic acid is possibly carcinogenic to humans (Group 2B).

For definition of the italicized terms, see Preamble Evaluation.


Last updated 01/22/98

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