Dimethyl sulphate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

Sensitising activity of DMS was tested in a murine local lymph node assay. Topical dosing of DMS (0.25, 0.5, and 1.0% in acetone/olive oil 80/20 v/v, number of animals not indicated) increased thymidine isotope incorporation in the lymph nodes more than 3-fold compared with vehicle-treated controls. A threefold increase was considered to be determinant of sensitising capacity (Ashby et al., 1995). It is noted that the positive response with DMS may be due to the corrosive properties. The Ear-Flank Test, however, showed an irregular reaction in a group of six guinea pigs treated with 10% DMS in olive oil. Interpretation of this result by the author was that DMS is a compound that does not cause sensitisation (Stevens, 1967). However this test is considered not suitable for evaluation, because the time between induction and challenge is considered to be too short.

Conclusion

The murine local lymph node assay can be used as a first stage in the assessment of skin sensitisation potential. A positive result indicates the test compound is a potential sensitiser and ‘it may not be necessary to conduct a further guinea pig test’ (OECD 406). The guinea pig test by Stevens (1967), a statement only, is not a standard test and provides only very limited information on the effects of DMS. Therefore this test is not suitable for evaluation. The data submitted are considered acceptable with regard to the basic requirements as specified in the Annex VIIA of Directive 67/548/EC under the restriction that the positive result in the LNA test is accepted.

Therefore, it is concluded that DMS is a potential sensitiser (R43).

Migrated from Short description of key information:
EU RISK ASSESSMENT – DIMETHYL SULPHATE