α,α,6,6-tetramethylbicyclo[3.1.1]hept-2-ene-2-propionaldehyde

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Ames test (similar to OECD TG 471): negative

In vitro micronucleus test (OECDTG487): not clastogenic or aneugenic

In vitro mouse lymphoma test (OECDTG490): not mutagenic

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Mode of Action Analysis / Human Relevance Framework

All in vitro genotoxicity tests are negative and therefore the substance does not have a genotoxic mode of action.

Additional information

Ames test

The mutagenic activity of the substance was evaluated according to the Japanese Guidelines for Screening Mutagenicity Testing of Chemicals (similar to OECD 471) and according to GLP principles. The test was performed with the pre-incubation method assay, both in the absence and presence of S9-mix. The dose levels were selected based on observed cytotoxicity in all strains. Adequate negative and positive controls were included. The substance did not induce a significant dose-related increase in the number of revertant (His+) colonies in each of the four S. typhimurium tester strains (TA1535, TA1537, TA98, TA100) and E.coli WP2, both in the absence and presence of S9-metabolic activation. Based on the results of this study, it is concluded that the substance is not mutagenic in the Salmonella typhimurium reverse mutation assay.

In vitro micronucleus test

In an in vitro micronucleus assay, cultured peripheral human lymphocytes were exposed to different concentrations of the substance (dissolved in ethanol), in the presence and absence of S9-mix according to OECD 487 guideline and GLP principles. In the first cytogenetic assay, the test item was tested up to and including 50 and 100 μg/mL for a 3 hours exposure time with a 27 hours harvest time in the absence and presence of S9-fraction, respectively. In the second cytogenetic assay, the test item was tested up to and including 65 μg/mL for a 24 hours exposure time with a 24 hours harvest time in the absence of S9-mix. The highest concentration analysed was selected based on toxicity, cytokinesis-block proliferation index of about 55 ± 5% in both tests. Reliable positive and negative controls were included. The substance did not induce a statistically significant or biologically relevant increase in the number of mono- and binucleated cells with micronuclei in the absence and presence of S9-mix, in either of the two experiments. It is concluded that the substance is not clastogenic or aneugenic in human lymphocytes.

In vitro mouse lymphoma assay

The mouse lymphoma assay with the substance was conducted according to OECD 490 guideline and GLP principles.

In the first experiment, the test item was tested up to and including concentrations of 22.5 and 40 μg/mL in the absence and presence of S9-mix, respectively. The incubation time was 3 hours. Relative total growth (RTG) was 48 and 27% in the absence and presence of S9-mix, respectively. The test item did not precipitated in the culture medium at this dose level. In the second experiment, the test item was tested up to and including concentrations of 22.5 μg/mL in the absence of S9-mix. The incubation time was 24 hours. The RTG was 19%. Positive control chemicals, methyl methanesulfonate and cyclophosphamide, both produced significant increases in the mutation frequency. In the absence of S9-mix, the substance did not induce a significant increase in the mutation frequency in the first experiment. This result was confirmed in an independent experiment with modification in the duration of treatment. In the presence of S9-mix, the substance did not induce a significant increase in the mutation frequency. It is concluded that the substance is not mutagenic in the mouse lymphoma L5178Y test system.

Justification for classification or non-classification

Based on the available data, the substance does not need to be classified for genotoxicity in accordance with the criteria outlined in EU CLP (EC. no 1272/2008 and its amendments).