Reaction product of 2-hydroxybenzoic acid, styrene and oxozinc

Endpoint summary

Additional information

The test item was dissolved in Dimethyl sulfoxide. In the Initial Mutation Test and Confirmatory Mutation Test the tested concentrations were: 5000; 1581; 500; 158.1; 50; 15.81 and 5 µg/plate. In the Complementary Confirmatory Mutation Test the tested concentrations were: 1581; 500; 158.1; 50; 15.81; 5; 1.581 and 0.5 µg/plate.

Five bacterial strains, Salmonella typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2 uvrA were used to investigate the mutagenic potential of Reaction product of 2-hydroxybenzoic acid, styrene and oxozinc in three independent experiments, in a plate incorporation test (Experiment I, Initial Mutation Test) and in two pre-incubation tests (Experiment II, Confirmatory Mutation Test and Experiments III, Complementary Confirmatory Mutation Test). Experiments I and II were carried out in the presence and absence of a post mitochondrial supernatant prepared from the livers of phenobarbital/β-naphthoflavone-induced rats (±S9-mix), while Experiment III was carried out only in absence of this metabolic activation. The concentrations, including the controls, were tested in triplicates. Using the plate incorporation method (Experiment I), none of the observed revertant colony numbers were above the respective biological threshold value. There were no dose-related trends and no indication of any treatment effect. Using the pre-incubation method (Experiments II and III), none of the observed revertant colony numbers were above the respective biological threshold value. There were no dose-related trends and no indication of any treatment effect. Strong cytotoxic effect (inhibited background lawn development and reduced number of revertant colonies) of the test item was observed in the Experiment II using the pre-incubation method. The observed cytotoxicity was confirmed in the Experiment III. Precipitate was observed in all of the tester strains at 5000 µg/plate concentration with and without metabolic activation in the Experiment I and II. Untreated, negative (solvent) and positive controls were run concurrently. The mean values of revertant colonies of the untreated and solvent control plates were within the historical control data range, the reference mutagens showed the expected increase in the number of revertant colonies, the viability of the bacterial cells was checked by a plating experiment in each test. The test bacteria demonstrated their typical responses to crystal violet and ampicillin. The tests were considered to be valid.

Short description of key information:
The reported data of an AMES test show, that the test item did not induce gene mutations by frameshift or base-pair substitution in the genome of the strains used. Therefore, Reaction product of 2-hydroxybenzoic acid, styrene and oxozinc is considered non-mutagenic in a bacterial reverse mutation assay.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on results of the in vitro genetic toxicity study (AMES test), Reaction product of 2-hydroxybenzoic acid, styrene and oxozinc was not classified and labelled as genotoxic according to Directive 67/548/EEC (DSD) and to Regulation (EC) No 1272/2008 (CLP).