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

(Group 2A)

For definition of Groups, see Preamble Evaluation.

VOL.: 71 (1999) (p. 1059)

CAS No.: 66-27-3
Chem. Abstr. Name: Methanesulfonic acid, methyl ester

5. Summary of Data Reported and Evaluation

5.1 Exposure data

Methyl methanesulfonate is a laboratory chemical that has been produced for research purposes. No information was available to the Working Group on potential human exposures.

5.2 Human carcinogenicity data

No data were available to the Working Group.

5.3 Animal carcinogenicity data

Methyl methanesulfonate was tested in rats by inhalation exposure and by subcutaneous and intraperitoneal administration, producing nasal tumours, tumours of the nervous system and tumours at the injection site. In rats, it was carcinogenic after administration of a single dose as well as following prenatal exposure. Following instillation into the bladder of rats, it potentiated the effect of N-methyl-N-nitrosourea. In one study, following oral administration in mice, it increased the incidence of lung tumours and of lymphomas. A subsequent experiment with oral and intraperitoneal administration to mice failed to increase the incidence of lung adenomas in A/J mice. In a multistage mouse skin model, it was not an initiator but was found to be a stage I tumour promoter. It accelerated the occurrence of thymic lymphomas in AKR mice.

5.4 Other relevant data

Methyl methanesulfonate caused an increased frequency of resorptions and congenital malformations after treatment of females 125 h after mating.

Methyl methanesulfonate induced mouse germ cell mutations and chromosomal aberrations, and DNA damage, micronuclei, sister chromatid exchanges and chromosomal aberrations in somatic cells of rodents in vivo. It increased the frequency of DNA damage, gene mutation, sister chromatid exchanges and micronuclei in human and rodent cell cultures, as well as chromosomal aberrations in rodent cells in vitro. Methyl methanesulfonate induced somatic and sex-linked mutations in Drosophila. It induced DNA damage in Escherichia coli and was mutagenic in bacteria.

5.5 Evaluation

No epidemiological data relevant to the carcinogenicity of methyl methanesulfonate were available.

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

Overall evaluation

Methyl methanesulfonate is probably carcinogenic to humans (Group 2A).

In making the overall evaluation, the Working Group took into consideration that methyl methanesulfonate is a direct-acting methylating agent which is mutagenic in a wide range of in-vivo and in-vitro test systems.

For definition of the italicized terms, see Preamble Evaluation.

Previous evaluations: Vol. 7 (1974); Suppl. 7 (1987)


Last updated: 13 April 1999

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       Toxicological Abbreviations