2-methylpyridine

Endpoint summary

Additional information

In an Ames bacterial reverse mutation assay (Kubo 2002) the test substance was evaluated for its potential genetic toxicity with and without metabolic activation using Salmonella typhimurium strains TA98 and TA100. A preincubation test was performed up to a concentration of 1 mM of the test substance. No information was available on bacteriotoxicity and negative controls. It was concluded that the test substance is not mutagenic.

In another Ames test (Aeschbacher 1989), the test substance was evaluated for its potential genetic toxicity with and without metabolic activation using Salmonella typhimurium strains TA98, TA100 and TA102 with and without metabolic activation. The test strains were exposed to 10 nmol - 1 mmol/plate (6 dose levels) in a preincubation test. No information was available on bacteriotoxicity. It was concluded that the test substance is not mutagenic.

In the evaulation report of the EFSA (2013) and US EPA (2009), four studies were described. The original reports were not available, but these reports are from reliable authorities and therefore adequate for assessment. Claxton et al (1987) published the results of an Ames assay (plate incorporation assay) with Salmonella typhimurium strains TA97, TA98, TA100 and TA102. Concentrations up to 5 mg/plate were tested both with and without metabolic activation. No other information was available. It was concluded that the test substance is not mutagenic. In another reverse-mutation bacterial assay (summarized by the EPA 2009), Salmonella typhimurium strains TA97, TA98, TA100, TA102, TA 1535 and/or TA 1537 were exposed to the test substance at concentrations up to 5000 μg/plate with and without metabolic activation. No bacteriotoxic effect were observed at these concentrations. The test substance was not mutagenic under these test conditions in the presence or absence of metabolic. Vleminckx et al. (1993; summarized in EFSA 2013) ) published the results of an Ames assay performed with Salmonella typhimurium strains TA98, TA100 and TA 1535 and TA 1537 with and without metabolic activation. The test substance was tested ( plate incorporation) at test concentrations of 50, 160, 500, 1600 and 5000 nL/plate (highest concentration: 4722 μg/plate). No other information was available. It was concluded that the test substance is not mutagenic under these experimental conditions. Vleminckx et al (1993; summarized in EFSA 2013 and EPA 2009) also published the results of a HGPRT gene mutation assay with Chinese hamster V79 lung cells. Test concentrations were 4.5, 4.75, 5, 5.25 and 5.5 μl/mL (highest concentration tested was 5194 μg/mL). Cytotoxic effects were observed at 5.25 μL/mL. No other information was available. It was therefore concluded that the test substance is not mutagenic under these experimental conditions. Schriewer et al (1993; summarized in 2013) published the results of an Alkaline elution assay performed to assess the potential of the test substance to cause single strand breaks in DNA from Chinese hamster V79 lung cells. The test substance was tested at 2, 3, 4, 5 and 6 μl/mL (highest dose tested: 5666 μg/mL). No genetoxic effects (single strand breaks) occurred. It was therefore concluded that the test substance is not mutagenic under these experimental conditions.

Florin et al (1980) tested test substance in an Ames bacterial reverse mutation assay (spot test) using Salmonella typhimurium strains TA 98, TA 100, TA 1535 and TA 1537 both with and without metabolic activation. All test strains were exposed to 3 µmol/plate (279 µg/plate) of the test substance. No bacteriotoxic effect was observed at this concentration. It was concluded that the test substance is not mutagenic under these experimental conditions. However, since only one dose had been tested being well below the required 5000 µg/plate, this study could not be used for risk assessment.

Zimmermann et al (1986) evaluated the test substance for its potential to induce mitotic aneuploidy, mitotic recombination and anti-tubulin effects in yeast strain S. cerevisiae D61.M. The test substance was considerd to be weakly active regarding induction of chromosome loss and other genetic changes, but did not induce anti-tubulin effects. However, the effects were observed at very high doses and the effect is considered to be thresholded. Therefore, this substance is not considered to be gentoxic in this study.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the assessment of all available genotoxicity tests classification in accordance with EU Directive 67/548/EEC (DSD) and EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008 is not warranted