C8-18 (even numbered) and C18 (unsaturated) sarcosinates, 2-hydroxypropylammonium salt

Endpoint summary

Additional information

A bacterial reverse mutation assay (Ames test) according to OECD guideline 471 was performed with the test substance (Verspeek-Rip, 2016). In this test the histidine-deficient Salmonella typhimurium strains TA1535, TA1537, TA98 and TA100 and the tryptophan-deficient Escherichia coli strain WP2uvrA were exposed to various test substance concentrations from 1.7 up to 5000 µg/plate in the absence and presence of a metabolising system (5 or 10% Aroclor 1254-induced rat liver S9-mix) in two independent experiments. Additional experiments were performed once with strains TA1535, TA1537, TA98 and TA100 and twice with strain TA98 alone in order to verify previous observations. In a preliminary range finding experiment the histidine-deficient Salmonella typhimurium strain TA100 and the tryptophan-deficient Escherichia coli strain WP2uvrA were exposed to test substance concentrations ranging from 1.7 to 5000 µg/plate in the absence and presence of 5% S9-mix. Based on the observations for cytotoxicity in this range finder the test substance was additionally tested in the strains TA1535, TA1537 and TA98 at concentrations ranging from 5.4 to 1600 µg/plate in the absence and from 17 to 1600 µg/plate in the presence of 5% S9-mix. Cytotoxicity evidenced by decrease of revertant numbers and/or reduction of background lawn was observed in all strains. No increase of revertant numbers was observed. The range finder in the tester strains TA100 and WP2uvrA combined with the additional results from strains TA1535, TA1537 and TA98 were regarded as Experiment 1. In a second experiment the test substance was tested at a concentration range of 154 to 2800 µg/plate in the absence and presence of 10% S9-mix in the S. typhimurium strains TA1535, TA1537, TA98 and TA100 and at 492 to 5000 µg/plate in the absence and presence of 10% S9-mix in the E. coli strain WP2uvrA. Cytotoxicity was observed in the S. typhimurium strains, but not in the E. coli strain. No increase in revertant numbers was observed in this experiment, either.

Since there were not enough analysable dose levels available in the second experiment due to cytotoxicity in various strains either with or without metabolic activation, an additional experiment was performed with the S. typhimurium strains TA1535, TA1537, TA98 and TA100 with lower test substance concentrations in the absence and presence of metabolic activation. Except for TA98 cytotoxiciy was observed in all tested strains in this third experiment. Furthermore, the test substance induced a 3.3-fold increase of revertants in strain TA98 without metabolic activation in this experiment. Therefore, an additional fourth experiment was performed with TA98 in the absence of metabolic activation up to 878 µg/plate. In this experiment no cytotoxicity and no increase of revertant numbers were observed. As there had been insufficient cytotoxicity in the absence of precipitation on the plates in this experiment, a fifth mutation experiment with TA98 without metabolic activation up to the dose level of 5000 µg/plate was performed. Cytotoxicity was observed, but there was no increase in the numbers of revertants in this confirmatory experiment, either.

Thus, the increase of revertant numbers observed in the third experiment could not be reproduced and was considered to be an isolated finding without biological relevance. In conclusion, the test substance was considered to be not mutagenic in the bacterial reverse mutation assay in Salmonella typhimurium and Escherichia coli.

Justification for selection of genetic toxicity endpoint
There is only one study available.

Short description of key information:
Mutagenicity in bacteria (Ames), OECD 471: negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

According to the criteria of the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments) and Regulation (EC) No 1271/2008 on classification, labelling and packaging of items and mixtures (including all amendments) the test substance does not have to be classified for genetic toxicity. The available data is conclusive but not sufficient for classification.