2-hydroxymethyl-9-methyl-6-(1-methylethyl)-1,4-dioxaspiro[4.5]decane

Endpoint summary

Additional information

In vitro gene mutation in bacteria

Two Ames studies are available addressing the in vitro gene mutation in bacteria. The key study is carried out according to the plate incorporation test using Salmonella typhimurium strains TA 1535, TA 1537, TA 1538, TA 98 and TA 100. The study was performed according to GLP and OECD and EU guidelines. The assay was performed in two independent experiments, using identical procedures, both with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test article was tested at the following concentrations: 1.0, 10.0, 33.3, 100.0, 333.3, 1000.0 and 5000.0 µg/plate.

 

During the described mutagenicity test and under the experimental conditions reported, the test article did not induce point mutations by base pair changes or frame shifts in the genome of the strains used. Therefore, the test substance is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

 

A similar outcome was found in the second Ames study that is available on the test substance.

 

 

In vitro gene mutation in mammalian cells

One study is available in which the potential of the test substance to induce mutations at the mouse lymphoma thymidine kinase locus using the cell line L5178Y is examined. The study was performed according to GLP and OECD guidelines.

The assay was performed in two independent experiments, using two parallel cultures each. The first main experiment was performed with and without liver microsomal activation and a treatment period of 4 h. The second experiment was performed with a treatment period of 24 hours in the absence of metabolic activation and 4 hours in the presence of metabolic activation. The highest concentration (2300 μg/mL) applied in the pre-experiment corresponds to a molar concentration of about 10 mM. The concentration range of both main experiments was limited by cytotoxic effects of the test item.

No substantial and reproducible dose dependent increase in mutant colony numbers was observed in both main experiments. It can therefore be concluded that during the mutagenicity test described and under the experimental conditions reported the test item did not induce mutations in the mouse lymphoma thymidine kinase locus assay using the cell line L5178Y in the absence and presence of metabolic activation. Therefore, the test substance is considered to be non-mutagenic in this mouse lymphoma assay.

 

In vivo chromosome aberrations

One key study is available in which the potential of the test substance to induce micronuclei in polychromatic erythrocytes (PCE) in the bone marrow of the mouse is examined.

The test article was formulated in polyethylene glycol 400 (PEG 400). The volume administered orally was 10 mL/kg bw. At 24h, 48h and 72h after a single application of the test article the bone marrow cells were collected for micronuclei analysis. Ten animals (5 males and 5 females) per test group were evaluated for the occurrence of micronuclei. 1000 Polychromatic erythrocytes (PCE) per animal were scored for micronuclei. To describe a cytotoxic effect due to the treatment with the test article the ratio between polychromatic and normochromatic erythrocytes (NCE) was determined in the same sample and reported as the number of NCE per 1000 PCE. The investigated dose level of the test article was 2500 mg/kg bw.

 

During the study described and under the experimental conditions reported, the test article did not induce micronuclei as determined by the micronucleus test with bone marrow cells of the mouse. Therefore, the test substance is considered to be non-mutagenic in this micronucleus assay.

 

Justification for selection of genetic toxicity endpoint
None of the available genotoxicity studies showed any evidence of genotoxic effects.

Short description of key information:
In total 3 in vitro studies are available that address gene mutations in bacteria and mammalian cells.
Furthermore, 1 in vivo study addresses the development of chromosome aberrations.
None of those studies resulted in a positive response. As a consequence, it can be conluded that the test substance does not exert gentoxic effects.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

As no genotoxic effects are observed in the available studies addressing the different endpoint of genetic toxicity, classification for genetic toxicity under EU Regulation No. 1272/2008 on the Classification, Labelling and Packaging of Substances and Mixtures (CLP) or Directive 67/548/EEC (Dangerous Substances Directive) is not required.