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

(Group 3)

For definition of Groups, see Preamble Evaluation.

VOL.: 63 (1995) (p. 373)

CAS No.: 4170-30-3
Chem. Abstr. Name: 2-Butenal

CAS No.: 15798-64-8
Chem. Abstr. Name: (Z)-2-Butenal (cis-isomer)

CAS No.: 123-73-9
Chem. Abstr. Name: (E)-2-Butenal (trans-isomer)

5. Summary and Evaluation

5.1 Exposure data

Crotonaldehyde is produced principally as an intermediate for the production of sorbic acid. It was formerly used in large amounts in the production of n-butanol.

Crotonaldehyde occurs naturally in foods and is formed during the combustion of fossil fuels (including engine exhausts), wood and tobacco and in heated cooking oils. Human exposure occurs from these sources and may occur during its production and use.

5.2 Human carcinogenicity data

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

5.3 Animal carcinogenicity data

Crotonaldehyde was tested for carcinogenicity in one study in male rats by administration in the drinking-water. Increased incidences of hepatic neoplastic nodules and altered liver-cell foci were seen, but these were not dose-related.

5.4 Other relevant data

Crotonaldehyde is a substrate for aldehyde dehydrogenase and forms conjugates with glutathione, in the presence or absence of glutathione transferase. Mercapturic acid metabolites have been identified in urine.

Crotonaldehyde is a potent irritant, and it has been reported to interfere with immune function.

Crotonaldehyde did not induce DNA damage in rat hepatocytes in vitro in a single study. It was mutagenic to insects and bacteria. It bound to DNA of mouse skin in vivo after topical application and to DNA in vitro and caused formation of DNA-protein cross-links.

5.5 Evaluation

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

There is inadequate evidence in experimental animals for the carcinogenicity of crotonaldehyde.

Overall evaluation

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

For definition of the italicized terms, see Preamble Evaluation.

Synonyms for Crotonaldehyde

Synonyms for cis Isomer

Synonyms for trans Isomer

Last updated 05/27/1997

    See Also:
       Toxicological Abbreviations
       Crotonaldehyde (ICSC)