1-vinylimidazole

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

1-Vinylimidazole did not cause gene mutations in Salmonella typhimurium and Escherichia coli (Ames test). The substance was also negative in HPRT and chromosome aberration studies. All studies were performed in the absence and presence of metabolic activation. Thus, 1-vinylimidazole is not considered to be genotoxic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

No in vivo mutagenicity data are available.

Endpoint conclusion

Endpoint conclusion:

no study available

Mode of Action Analysis / Human Relevance Framework

not specified

Additional information

1-Vinylimidazole was tested in the Ames reverse mutation assay (GLP- compliant study according to OECD471 and 472, 1997; RL1) using Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 and Escherichia coli WP2 uvr A at 33.3 to 5000 µg/plate (standard plate and preincubation test) with and without metabolic activation (CCR, 1997). 1-Vinyl-imidazole was not cytotoxic nor mutagenic in any of the S. typhimurium strains and E.coli WP2 uvr A under the conditions tested.

In a supporting study, equivalent to OECD471, 1-vinylimidazole was tested in the reverse mutation assay usingSalmonella typhimuriumstrains TA98, TA100, TA1535 and TA1537 at 20 to 5000 µg/plate (standard plate and preincubation test) with and without metabolic activation (1989; RL2). 1-Vinylimidazole was cytotoxic only in the 1st standard plate test without S-9 mix using TA 1537. Under the conditions tested, 1-vinylimidazole was not mutagenic in any of theS. typhimuriumstrains.

1-Vinylimidazole was also tested in a GLP-compliant gene mutation test in Chinese hamster ovary cells (HPRT locus assay tested according to OECD476, 1993; RL1). Cells were treated with 1-vinylimidazole for 4 hours in two experiments at concentrations ranging from 0.05 to 10 mg/mL in the first test and from 0.6 to 6 mg/mL in the second test, both tests were performed with and without S-9 mix. Markedly reduced cell densities were found at the first subcultivation to concentrations > 5 mg/mL in all experiments. Cloning efficiencies were reduced at concentrations of ≥ 7.5 mg/mL (18 - 20 h post exposure). No biologically significant increases in mutant frequency were observed in either of the experiments with and without metabolic activation. It is concluded that 1-vinylimidazole is not mutagenic under the test conditions employed in this in vitro test system.

 

Furthermore, a GLP-compliant in vitro mammalian chromosome aberration test with Chinese hamster lung fibroblasts (V79) tested according to OECD473 is available (1993; RL1). Cells (slide cultures in Quadriperm dishes) were exposed to 1-vinylimidazole for ca. 24 hours at concentrations ranging from 625 to 5000 µg/mL with and without S-9 mix. After 18 h 1250, 2500 and 5000 µg/mL both with and without S9 mix were examined for chromosome aberrations. After 28 h only the 5000 µg/mL dose was examined. There was no relevant increase of the aberration rates in the cultures treated with the test substance compared to the negative controls. By contrast, a marked rise in the incidence of aberrant metaphases was observed in the positive controls with known mutagens. Apart from gaps and breaks mainly chromatid exchanges, dicentric chromosomes and multiple aberrations were observed. Numerical aberrations in the form of polyploids were not influenced by the test article. Under the test conditions, induction of structural chromosome aberrations and numerical aberrations in the form of polyploids by the substance 1-vinylimidazole can be ruled out.

 

No in vivo data are available.

Justification for classification or non-classification

Based on the results of the in vitro mutagenicity tests, 1-vinylimidazole does not need to be classified according to the EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No. 1272/2008.