Tetrahydro-4-methyl-2-(2-methylprop-1-enyl)pyran

Endpoint summary

Additional information

In vitro mutagenicity in bacteria:

In the chosen key study according to OECD TG 471 and GLP, the mutagenic effect of rose oxide was determined in a reverse mutation assay using S. typhimurium strains TA 97a, TA 98, TA 100, TA 102 and TA 1535 with and without metabolic activation (Symrise 2001). Cytotoxicity was observed, starting at 1.6 mg/plate. No relevant increase in the number of revertant colonies was found. Therefore, rose oxide was found to be non-mutagenic under the chosen test conditions.

In vitro mutagenicity in mammalian cells:

In the chose key study according to OECD TG 476 and GLP, the potential of rose oxide to induce gene mutations at the HPRT locus in V79 Chinese hamster cells was investigated (BASF 2012; 50M0624/07X024). The assay was performed in two independent experiments, using two parallel cultures each with and without liver microsomal activation and a treatment period of 4 or 24 hours. No substantial and reproducible dose dependent increase of the mutation frequency was observed up to the maximum concentration with and without metabolic activation. Appropriate positive controls (EMS and DMBA) induced a distinct increase in mutant colonies and thus, showed the sensitivity of the test system and the activity of the metabolic activation system. In conclusion, it can be stated that under the chosen experimental conditions, rose oxide did not induce gene mutations at the HPRT locus in V79 cells and is therefore considered to be non-mutagenic in this HPRT assay.

Genetic toxicity in vivo:

In the chose key study according to OECD TG 474 and GLP, the potential of rose oxide to induce micronuclei in male NMRI mice was investigated (BASF 2012; 26M0624/07M014). Rose oxide dissolved in corn oil, was administered once orally at dose levels of 250 mg/kg, 500 mg/kg and 1000 mg/kg body weight in a volume of 10 mL/kg body weight each in two independent experiments. A weak increase in the frequency of micronucleated PCEs has been observed, however due to a large inter-animal variability, absence of statistical significance and similar maximum PCE values per animal in control and treatment groups, this observation has to be regarded as biologically irrelevant.Thus, under the experimental conditions of this study, based on the data of two independently performed experiments it has to be concluded that rose oxide does not induce cytogenetic damage in bone marrow cells of NMRI mice in vivo.

Short description of key information:
In vitro mutagenicity in bacteria (Ames test acc. to OECD TG 471 and GLP): negative (Symrise 2001)
In vitro mutagenicity in mammalian cells (HPRT test acc. to OECD TG 476 and GLP): negative (BASF 2012; 50M0624/07X024)
In vivo mutagenicity (MNT test in mice acc. to OECD TG 474 and GLP): negative (BASF 2012; 26M0624/07M014)

Endpoint Conclusion:

Justification for classification or non-classification

The present data on genetic toxicity do not fulfill the criteria laid down in 67/548/EEC and CLP, and therefore, a non-classification is warranted.