N,N'-(methylenedi-p-phenylene)bis[hexahydro-2-oxo-1H-azepine-1-carboxamide]

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Short description of key information: Test article revealed negative mutagenic activity in the bacterial and cultured mammalian somatic cells under the experimental conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In vitro:

There were three study reports (Judit Hargitai, PhD.,2012; Dr. rer. nat. C. Flügge, 2012, Renata Chladova, 2012) following OECD guidelines (471, 476 and 487, respectively) and GLP principle to evaluate the mutagenic potential of test article.

Based on the results of an Ames test, the test article showed negative mutagenicity. This study was conducted to investigate the mutagenic potential of test substance with histidine-requiring auxotroph strains of Salmonella typhimurium (Salmonella typhimurium TA98, TA100, TA1535 and TA1537), and the tryptophan-requiring auxotroph strain of Escherichia coli (Escherichia coli WP2 uvrA) in the presence and absence of a metabolic activation system. Based on the results of the range finding test, the test item concentrations in the main tests were 5000, 1581, 500, 158.1, 50, 15.81, 5 and 1.581 μg test item/plate. Evidence of mutagenic activity of test substance was not seen. No biologically relevant increase in the mutant count, in comparison with the negative controls, was observed.

In the in vitro gene mutation test, there was consistent result with that of the Ames test.

This study was performed to evaluate the mutagenic potential of test item in a gene mutation assay in cultured mammalian cells (V79, genetic marker HPRT) both in the presence and absence of metabolic activation. In conclusion, the test article was therefore considered to be non-mutagenic without and with S9 mix in the genetic test. The duration of the exposure with the test item was 4 hours or 24 hours in the experiments without S9 mix and 4 hours in the experiments with S9 mix. Cytotoxicity in form of decreased plating efficiency (PE1) and (PE2) was noted in the first and second experiments at the top concentrations 200 µg/mL in the absence and presence of metabolic activation. The mutation frequency of the cultures treated with all concentrations is within the normal range of the vehicle controls.

Finally, in the in vitro micronucleus test, human peripheral blood lymphocytes were employed both with and without metabolic activation system in two separate assays. The concentrations of 0.05, 0.1, 0.2, 0.5, 1, 3 and 5 mg/ml of final culture were used in the preliminary test. Five dose levels were used both with and without metabolic activation in the main test: 0.0125, 0.025, 0.05, 0.1 and 0.2 mg/ml of final culture. There was no significant increase in the number of binucleate cells with micronuclei and no dose-response relationship in the main test. In the repeated test no increase in the percentage value of aberrant cells was observed and no dose-response relationship was observed, neither.

In vivo:

According to Chapter R.7a: Endpoint specific guidance, table R.7.7-5, row 4, no further tests are required since available data (negative results from in vitro gene mutation in bacteria, cytogenicity study in vitro and gene mutation in mammalian cells) is sufficient to conclude that test article is non-mutagenic.

 

Therefore, these negative results as above indicate that, under the test conditions used, the test item does not induce mutagenic activity in bacterial and cultured mammalian somatic cells.

Justification for classification or non-classification

Based on the available data, the test article is not being classified in accordance with CLP (Regulation EC No. 1272/2008) for mutagenicity.