3-Pentanone, 1-(2,6,6-trimethyl-2-cyclohexen-1-yl)-, reaction products with 2-propyn-1-ol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test (OECD TG 471): not mutagenic

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Additional information

Ames test:

The mutagenic activity of the substance was evaluated in accordance with OECD 471 (1997) guideline and according to GLP principles. The test was performed in two independent experiments: at first a direct plate assay was performed in the absence and presence of S9-mix up to and including the precipitating concentration of 5000 μg/plate. The bacterial background lawn was not reduced at any of the concentrations tested and no biologically relevant decrease in the number of revertants was observed.

Secondly a pre-incubation assay was performed in the absence and presence of S9-mix up to and including the precipitating concentration of 1600 μg/plate. Cytotoxicity, as evidenced by a decrease in the bacterial background lawn and/or decrease in the number of revertants was observed in several tester strains, TA1535 (absence and presence of S9-mix), TA1537 (absence of S9-mix), and TA100 (absence and presence of S9-mix). Since in the second mutation experiment, only dose levels with cytotoxicity were present in the tester strains TA1535 and TA100 in the absence of S9-mix, an additional pre-incubation experiment was performed. In this third mutation experiment, the test item was tested at a concentration range of 1.7 to 512 μg/plate in tester strain TA1535 and 0.056 to 52 μg/plate in tester strain TA100. The test item did not precipitate on the plates at these dose levels. Cytotoxicity, as evidenced by a decrease in the number of revertants and/or bacterial background lawn, was observed in both tester strains. Since in the third mutation experiment, only dose levels with cytotoxicity were present in tester strain TA1535, an additional pre-incubation experiment was performed. In this fourth mutation experiment, the test item was tested at a concentration range of 0.056 to 52 μg/plate. Acceptable responses were obtained for the negative and strain-specific positive control items indicating that the test conditions were adequate and that the metabolic activation system functioned properly. The substance did not induce a significant dose-related increase in the number of revertant (His+) colonies in each of the four tester strains (TA1535, TA1537, TA98 and TA100) and in the number of revertant (Trp+) colonies in tester strain WP2uvrA both in the absence and presence of S9-metabolic activation. These results were confirmed in an independently repeated experiment. Based on the results of this study it is concluded that the substance is not mutagenic in the Salmonella typhimurium reverse mutation assay and in the Escherichia coli reverse mutation assay.

Justification for classification or non-classification

Based on the results of the Ames test, the test substance does not have to be classified for mutagenicity, according to Regulation (EC) No. 1272/2008 and its amendments.