1-(2,4,6-trichlorophenyl)acetone O-methyloxime

Endpoint summary

Additional information

Mammalian chromosomal aberration test

In order to assess the potential of the test item to induce structural chromosomal aberrations in cultured human lymphocytes, Bohnenberger 2014 conducted a study following recent guidelines and in compliance with GLP. In each experimental group two parallel cultures were analysed, in the absence and presence of an exogenous metabolic activation system (liver S9 mix from phenobarbital / beta-naphthoflavone treated male rats). Either with or without metabolic activation, no clastogenicity was observed at the concentrations evaluated. No evidence of an increase in polyploid metaphases was noticed after treatment with the test substance as compared to the control cultures. Appropriate mutagens were used as positive controls. They induced statistically significant increases (p < 0.05) in cells with structural chromosome aberrations.

Based on the available data which is considered to be complete, reliable and conclusive for Genetic toxicity, the substance is considered to be non-clastogenic.

Bacterial Reverse Mutation Test (Ames)

This study was performed to investigate the potential of the substance to induce gene mutations in the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella typhimurium strains, and Escherichia coli strains. No cytotoxic effects, evident as a reduction in the number of revertants (below the indication factor of 0.5), were observed in any of the bacterial strains. No increase in revertant colony numbers of any of the six tester strains was observed following treatment with the test item at any concentration level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance. Appropriate reference mutagens were used as positive controls. They showed a distinct increase of induced revertant colonies.

Based on the available data which is considered to be complete, reliable and conclusive for Genetic toxicity, the substance is considered to be non-mutagenic.

In accordance with Regulation (EC) No. 1907/2006, Annex VII, 8.4.1, the available data is considered complete and adequate for the purposes of risk assessment and classification.

Justification for selection of genetic toxicity endpoint
Both available studies provide valid information on genotoxicity and chromosome aberration.

Short description of key information:
Negative, Chromosome aberration, OECD 473, Bohnenberger 2014
Negative, Ames test, OECD 471, Sokolowski 2014

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

A chromosome aberration study and a bacterial reverse mutation test were conducted following OECD guidelines and in compliance with GLP Directive 2004/10/EC. The result are valid, reliable and adequate for the purpose of risk assessment, classification and labelling.

The substance does not meet the criteria for classification as a germ cell mutagen according to Regulation (EC) 1272/2008, 3.5.2.