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

a-CHLORINATED TOLUENES
AND BENZOYL CHLORIDE
(COMBINED EXPOSURES)
(Group 2A)

For definition of Groups, see Preamble Evaluation.

VOL.: 71 (1999) (p. 453)

Benzyl chloride
CAS No.: 100-44-7
Chem. Abstr. Name: (Chloromethyl)benzene

Benzal chloride
CAS No.: 98-87-3
Chem. Abstr. Name: (Dichloromethyl)benzene

Benzotrichloride
CAS No.: 98-07-7
Chem. Abstr. Name: (Trichloromethyl)benzene

Benzoyl chloride
CAS No.: 98-88-4
Chem. Abstr. Name: Benzoyl chloride

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Little information on occupational or environmental exposures to these chemicals was available to the Working Group.

5.2 Human carcinogenicity data

Small cohort studies of occupational exposures to a-chlorinated toluenes and benzoyl chloride in the United States and England each noted an approximately three-fold excess of lung cancer.

5.3 Animal carcinogenicity data

Benzyl chloride, benzal chloride, benzotrichloride and benzoyl chloride have been studied by skin application to mice. Small numbers of skin tumours were produced by benzyl chloride and benzoyl chloride, while clear increases in skin tumours were produced by benzal chloride and benzotrichloride. Following subcutaneous injections to rats, benzyl chloride produced some injection site tumours. Administration by gavage of benzyl chloride to mice and rats produced forestomach tumours in mice and a few neoplasms of the forestomach were observed in male rats. Benzotrichloride administered by gavage to mice produced tumours of the forestomach and lungs. In addition, benzotrichloride and benzoyl chloride were administered by inhalation to mice: benzotrichloride produced increases in the incidences of tumours of the lung and skin, whereas no significant increase in tumour incidence was observed after benzoyl chloride administration.

5.4 Other relevant data

No studies were available on the disposition of benzotrichloride, benzal chloride or benzoyl chloride. Benzyl chloride is rapidly absorbed and distributed from the gastrointestinal tract. Excretion is mainly in urine as S-benzyl-N-acetylcysteine, benzyl alcohol and benzaldehyde.

All of the compounds are irritant to the skin and mucous membranes.

Benzyl chloride, benzal chloride and benzotrichloride, but not benzoyl chloride, are bacterial mutagens. Only benzyl chloride has been more extensively tested. It is genotoxic to fungi, Drosophila melanogaster and cultured mammalian cells, but did not increase the frequency of micronuclei in mice.

5.5 Evaluation

There is limited evidence in humans for the carcinogenicity of a-chlorinated toluenes and benzoyl chloride.

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

There is limited evidence in experimental animals for the carcinogenicity of benzal chloride.

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

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

Overall evaluation

Combined exposures to a-chlorinated toluenes and benzoyl chloride are probably carcinogenic to humans (Group 2A).

Previous evaluations: Vol. 29 (1982) (benzoyl chloride); Suppl. 7 (1987) (benzoyl chloride)

Synonyms

Benzyl chloride

Benzal chloride

Benzotrichloride

Benzoyl chloride


Last updated: 12 April 1999





















    See Also:
       Toxicological Abbreviations