3-methyl-1-vinyl-1H-imidazolium methyl sulphate

Endpoint summary

Additional information

Genetic toxicity in vitro

Ames-Test

The test substance 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay according to OECD 471 guideline and GLP (BASF SE, 2012).

STRAINS: TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA

DOSE RANGE: 33 μg - 5 000 μg/plate (SPT) 33 μg - 5 000 μg/plate (PIT)

TEST CONDITIONS: Standard plate test (SPT) and preincubation test (PIT) both with and without metabolic activation (liver S9 mix from induced rats).

SOLUBILITY: No precipitation of the test substance was found with and without S9 mix.

TOXICITY: A bacteriotoxic effect was observed depending on the strain and test conditions from about 333 μg/plate onward. MUTAGENICITY: A relevant increase in the number of his+ or trp+ revertants was not observed in the standard plate test or in the preincubation test either without S9 mix or after the addition of a metabolizing system.

CONCLUSION: Thus, under the experimental conditions of this study, the test substance 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.

Chromosome aberration test:

The test substance 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate was analysed for its potential to induce chromosomal aberration in mammalian V79 cells of the chinese hamster according to OECD guideline 473 and GLP. Four independent experiments were performed. In Experiment IA the exposure period was 4 hours with and without S9 mix. In Experiment IB the exposure period was 4 hours with S9 mix. In Experiment IIA the exposure period was 18 and 28 hours without S9 mix and 4 hours with S9 mix. In Experiment IIB the exposure period was 18 hours without S9 mix and 4 hours with S9 mix. The chromosomes were prepared 18 and 28 hours after start of treatment with the test item. The highest treatment concentration in this study, 2202.0 µg/mL (approx. 10 mM) was chosen with regard to the molecular weight of the test item and with respect to the OECD Guideline for in vitro mammalian cytogenetic tests.

In all experimental parts in the absence of S9 mix and in Experiment IB, IIA and IIB in the presence of S9 mix, no biologically relevant increase in the number of cells carrying structural chromosome aberrations was observed. The aberration rates of the cells after treatment were within the control values (0.5 - 2.5 % aberrant cells, excluding gaps) and within the range of the laboratory historical solvent control data. In Experiment IA a single increase in cells carrying chromosomal aberrations was observed in the presence of S9 mix after treatment with 550.5 µg/mL (8.5 % aberrant cells, excluding gaps). The value was statistically significant and exceeded the range of the historical control data (0.0 - 4.0 % aberrant cells, excluding gaps). In the confirmatory Experiment IB with S9 mix one single value (3.5 % aberrant cells, excluding gaps) was statistically significant. This value is in the range of the historical solvent control data (0.0 - 4.0 % aberrant cells, excluding gaps) and can therefore be regarded as biologically irrelevant. Thus, the positive finding of Experiment IA could not be confirmed. No biologically relevant increase in the rate of polyploid metaphases was found after treatment with the test item (1.3 - 3.8 %) as compared to the rates of the solvent controls (1.9 - 4.8 %). Furthermore, No biologically relevant increase in the rate of endomitotic metaphases was found after treatment with the test item (0.0 - 0.7 %) as compared to the rates of the solvent controls (0.0 - 1.3 %).

In conclusion, it can be stated that under the experimental conditions reported, the test item 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate did not induce structural chromosomal aberrations in V79 cells of the Chinese hamster in vitro.

HPRT-Assay:

A GLP-compliant gene mutation assay, tested according to OECD guideline 476, was performed to investigate the potential of 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate to induce gene mutations at the HPRT locus in V79 cells of the Chinese hamster (Harlan 2012).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 hours. The second experiment was performed with a treatment time of 4 hours with and 24 hours without metabolic activation.The test item was dissolved in deionised water.The concentration range of the main experiments was limited by cytotoxic effects of the test item. Relevant cytotoxic effects occurred in the first experiment at 138.8μg/mL and above without metabolic activation and in the second experiment at 555μg/mL and above without metabolic activation. The recommended cytotoxic range of approximately 10-20% relative cloning efficiency I or relative cell density was covered without metabolic activation.Precipitation of the test item was noted at 555.0μg/mL and above in experiment I with metabolic activation. In experiment II precipitation occurred at 555.0μg/mL without metabolic activation and at 277.5μg/mL and above with metabolic activation.No substantial and reproducible dose dependent increase of the mutation frequency was observed up to the maximum concentration with and without metabolic activation.Therefore, 3-Methyl-1-vinyl-1 H-imidazolium methyl sulfate is considered to be non-mutagenic in this HPRT assay.

Short description of key information:
Ames-Test (OECD 471): negative (BASF SE, 2012)
Chromosome aberration test (OECD 473): negative (Harlan, 212)
HPRT-Assay (OECD 476): negative (Harlan, 2012)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data from three in vitro studies (Ames-Test, HPRT-Assay, Chromosome Aberration Test), no classification for genetic toxicity according to EU Directive 67/548/EEC and EU classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No 1272/2008 is warranted.