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

(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 63 (1995) (p. 271)
CAS No.: 79-43-6
Chem. Abstr. Name: Dichloroacetic acid

5. Summary and Evaluation

5.1 Exposure data

Dichloroacetic acid is produced commercially in small quantities for use as an intermediate in the production of glyoxylic acid, dialkyloxy and diaryloxy acids and sulfonamides. Human exposure may occur during the production and use of dichloroacetic acid and from drinking chlorinated water.

5.2 Human carcinogenicity data

The available data were too limited to form the basis for an evaluation of the carcinogenicity of dichloroacetic acid to humans.

5.3 Animal carcinogenicity data

Neutralized dichloroacetic acid was tested by oral administration in males of one strain of mice in four studies. Increased incidences of hepatocellular adenomas and carcinomas were observed in all of the studies.

5.4 Other relevant data

Dichloroacetic acid is metabolized in humans and experimental animals, and oxalate, thiodiacetic acid and unchanged dichloroacetic acid are excreted in urine. Clearance is decreased in humans after repeated administration. Species differences in the clearance of dichloroacetic acid are observed in rodents: clearance in rats is much slower than in mice. Dichloroacetic acid induces peroxisome proliferation in the livers of both rats and mice.

No data were available on the effects of dichloroacetic acid on human reproduction. In rats and dogs, testicular degeneration can occur after exposure to this compound. The development of the heart, major vessels and kidney of rats can be affected by exposure in utero.

The evidence for induction of DNA strand breaks in liver cells of rodents exposed to dichloroacetic acid in vivo was inconclusive. Strand breaks were not induced in human or rodent cells in vitro. The results of assays for mutagenesis in bacteria were inconsistent.

The spectrum of mutations in H-ras proto-oncogenes in hepatic tumours from mice treated with dichloroacetic acid was different from that seen in hepatic tumours from untreated mice.

5.5 Evaluation

There is inadequate evidence in humans for the carcinogenicity of dichloroacetic acid.

There is limited evidence in experimental animals for the carcinogenicity of dichloroacetic acid.

Overall evaluation

Dichloroacetic acid is not classifiable as to its carcinogenicity to humans (Group 3).

For definition of the italicized terms, see Preamble Evaluation.


Last updated 05/27/1997

    See Also:
       Toxicological Abbreviations
       Dichloroacetic acid (ICSC)
       Dichloroacetic acid (IARC Summary & Evaluation, Volume 84, 2004)