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Administrative data

Key value for chemical safety assessment

Additional information

There are three in vitro studies available addressing mutagenicity in bacteria, and clastogenicity and mutagenicity in mammalian cells, all conducted with CAS 66455-29-6 (with which Betaines, C12-14 (even numbered)-alkyldimethyl was previously referred to), which are acceptable for assessment.

 

Mutagenicity in bacteria was investigated by the Bacterial Reverse Mutation Assay (Ames test) with 5 strains of Salmonella typhimurium (Fiebig, 2003). In this study the tested bacteria strains TA97a, TA98, TA100, TA1535 and TA102 were exposed to respective concentrations of 0.016 to 5.000 mg/plate and 0.005 to 1.600 mg/plate of CAS 66455-29-6 in two independent experiments for 48 hours with or without metabolic activation by phenobarbital- and beta-naphtoflavone-induced rat liver S9. Depending on the strain and the application of metabolic activation the upper and lower concentrations of the applied concentration ranges varied within each experiment. Under the conditions of the study the test substance did not induce gene mutations in the tested strains. Cytotoxic effects were observed starting at 1.6 and 0.5 mg/plate with and without S9, respectively, in TA97a, 5.0 and 1.6 mg/plate with and without S9, respectively, in both TA98 and TA1535, 5.0 mg/plate with and without S9 in TA102, and 1.6 mg/plate without S9 only in TA100.

 

The ability to induce clastogenic effects in mammalian cells was investigated with the In Vitro Chromosome Aberration Test (Madraymootoo, 2010), performed in Chinese Hamster Ovary cells (CHO K1 cells) with and without metabolic activation by Aroclor 1254-induced rat liver S9. Cells were exposed to the test article CAS 66455-29-6 for 4 or 20 hours without S9-mix, and for 4 hours only with S9. Cells were exposed to maximal concentrations of 150 and 200 µg/mL in the 4-hour exposure groups with and without S9, respectively, and to 100 µg/mL in the 20-hour exposure group without S9. Cytotoxicity was observed at concentrations higher than 280 µg/mL in the 4-hour exposure groups with and without S9, and at concentrations higher than 84 µg/mL in the non-activated 20-hour exposure group in a preliminary toxicity assay which served as range finder for the actual study. Under the conditions of the study the tested alkyl dimethyl betaine did not induce chromosomal aberrations in the CHO cells. Therefore, Betaines, C12-14 (even numbered)-alkyldimethyl which was previously referred to by CAS 66455-29-6, does not have to be considered as clastogenic.

Gene mutation in mammalian cells was addressed by a CHO/HGPRT Mutation Assay in Chinese Hamster Ovary cells (CHO K1) with CAS 66455-29-6 (Clarke, 2010). In a preliminary range-finder concentrations up to 2790 µg/mL were tested with and without metabolic activation by Aroclor 1254-induced rat liver S9. As no precipitation occurred up to the highest concentration, the actual concentrations for the test were chosen based on cloning efficiency. Substantial toxicity, i.e. cloning efficiency lower than 50%, was observed at concentrations equal to or greater than 50 µg/mL without activation and at concentrations equal to or greater than 150 µg/mL with activation in the preliminary toxicity assay. Based on these findings the concentrations chosen for the mutagenesis assay ranged from 5.0 to 150 µg/mL for the non-activated cultures and from 5.0 to 200 µg/mL for the activated ones. In the actual mutagenesis assay no visible precipitate was observed in the treatment medium, either. Toxicity, i.e. cloning efficiency equal to or lower than 50% of the solvent control, was observed at concentrations equal to or greater than 50 µg/mL without activation and 100 µg/mL with activation. Under the conditions of the study the test substance was negative in the CHO/HGPRT Mutation Assay, i.e. no treated cultures with mutant frequencies higher than 40 mutants per 10E6 clonable cells were observed..

According to Regulation (EC) No 1907/2006, Annex VIII, section 8.4, column 2, an in vivo mutagenicity study does not have to be considered as there were no positive results obtained from any of the in vitro genotoxicity studies in Annex VII and VIII.

Justification for selection of genetic toxicity endpoint

No study was selected, since all available in vitro genetic toxicity studies refer to different endpoints and were all negative.

Short description of key information:

In vitro:

Bacterial reverse mutation assay (OECD 471): negative with and without metabolic activation

Mammalian chromosome aberration test (OECD 473): negative with and without metabolic activation

Mammalian cell gene mutation test (OECD 476): negative with and without metabolic activation

In vivo:

Data waiving - not required

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The test material does not demonstrate mutagenic or clastogenic effects in bacteria or mammalian cells in vitro. Therefore, Betaines, C12-14 (even numbered)-alkyldimethyl does not have to be classifed for genetic toxicity according to the criteria of EU Directive 67/548/EEC or Regulation (EC) No 1272/2008.