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


VOL.: 32 (1983) (p. 211)

CAS No.: 50-32-8
Chem. Abstr. Name: Benzo(a)pyrene

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Benzo[a]pyrene has been shown to be carcinogenic to experimental animals.

Benzo[a]pyrene is embryotoxic and teratogenic in mice; the inducibility of aryl hydrocarbon hydroxylase activity in dams and fetuses is an important factor in determining these effects. A reduction in fertility in both male and female offspring was observed in mice following exposure to benzo[a]pyrene in utero.

Benzo[a]pyrene undergoes metabolism to reactive electrophiles capable of binding covalently to DNA. It was active in assays for bacterial DNA repair, bacteriophage induction and bacterial mutation; mutation in Drosophila melanogaster; DNA binding, DNA repair, sister chromatid exchange, chromosomal aberrations, point mutation and transformation in mammalian cells in culture; and in tests in mammals in vivo, including DNA binding, sister chromatid exchange, chromosomal aberration, sperm abnormality and the somatic specific locus (spot) test.

There is sufficient evidence that benzo[a]pyrene is active in short-term tests.

5.2 Human data

Benzo[a]pyrene is present as a component of the total content of polynuclear aromatic compounds in the environment. Human exposure to benzo[a]pyrene occurs primarily through the smoking of tobacco, inhalation of polluted air and by ingestion of food and water contaminated by combustion effluents.

5.3 Evaluation

There is sufficient evidence that benzo[a]pyrene is carcinogenic to experimental animals.

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluation: Vol. 3 (1973)

Subsequent evaluation: Suppl. 7 (1987) (p. 58: Group 2A)


Last updated: 17 April 1998

    See Also:
       Toxicological Abbreviations
       Benzo[a]pyrene (WHO Food Additives Series 28)
       BENZO[a]PYRENE (JECFA Evaluation)