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Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

The test material was considered to be non-mutagenic under the conditions of the Ames test (OECD 471, EU Method B.13/14, EPA OCSPP 870.5100 and relevant Japanese guidelines)

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Ames test

The test method was designed to be compatible with the guidelines for bacterial mutagenicity testing published by the major Japanese Regulatory Authorities including METI, MHLW and MAFF, the OECD Guidelines for Testing of Chemicals No. 471 "Bacterial Reverse Mutation Test", Method B13/14 of Commission Regulation (EC) number 440/2008 of 30 May 2008 and the USA, EPA OCSPP harmonized guideline - Bacterial Reverse Mutation Test.

Salmonella typhimuriumstrains TA1535, TA1537, TA98 and TA100 and Escherichia coli strain WP2uvrA were treated with the test item using the Ames plate incorporation method atup to eight dose levels, in triplicate, both with and without the addition of a rat liverhomogenate metabolizing system (10 % liver S9 in standard co-factors). The dose range for Experiment 1 was predetermined and was 1.5 to 5000μg/plate. The experiment was repeated on a separate day using fresh cultures of the bacterial strains and fresh test item formulations. The dose range was amended following the results of Experiment 1 and was 15 to 5000 μg/plate. Six test item dose levels were selected in Experiment 2 in order to achieve both a minimum of four non-toxic dose levels and the potential toxic limit of the test item.

The vehicle (tetrahydrofuran) control plates gave counts of revertant colonies within the normal range. All of the positive control chemicals used in the test induced marked increases in the frequency of revertant colonies, both with or without metabolic activation. Thus, the sensitivity of the assay and the efficacy of the S9-mix were validated. The maximum dose level of the test item in the first experiment was selected as the maximum recommended dose level of 5000 μg/plate. There was no visible reduction in the growth of the bacterial background lawn at any dose level, either in the presence or absence of metabolic activation (S9-mix), in the first mutation test and consequently the same maximum dose level was used in the second mutation test. Similarly there was no visible reduction in the growth of the bacterial background lawn at any dose level, either in the presence or absence of metabolic activation (S9-mix), in the second mutation test.

A test item precipitate (globular in appearance) was noted under a low power microscope at 1500 μg/plate and by eye at 5000 μg/plate, this observation did not prevent the scoring of revertant colonies. There were no toxicologically significant increases in the frequency of revertant colonies recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in Experiment 1. Similarly, no toxicologically significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test item, either with or without metabolic activation (S9-mix) in Experiment 2. Small, statistically significant increases in TA98 revertant colony frequency were observed in the first mutation test (presence of S9-mix only) at 500 μg/plate and in the second mutation test at 500 and 1500 μg/plate (absence of S9-mix only). These increases were considered to be of no biological relevance because there was no evidence of reproducibility or a meaningful dose-response relationship (the responses were flat at each statistically significant dose level). Furthermore, the individual revertant counts at the statistically significant dose levels were within the in-house historical untreated/vehicle control range for the tester strain and the maximum fold increase was only 1.6 times the concurrent vehicle controls. The test item was considered to be non-mutagenic under the conditions of this test.

Justification for classification or non-classification

The test material was considered to be non-mutagenic under the conditions of the Ames test and classification under the terms of Regulation (EC) No 1272/2008 is not required