Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

In vitro

An Ames test was conducted with the read-across substance C16 TMAC (25% purity) (pre-experiment and experiment I) and the pre-incubation test (experiment II) usingSalmonella typhimuriumstrains TA 1535, TA 1537, TA 98 and TA 100 andEscherichia colistrain WP2 uvrA. The assay was performed in three independent experiments both with and without S9 mix. All positive control mutagens used in the study showed a distinct increase of induced revertant colonies. Strong toxic effects, evident as a reduction in the number of revertants, occurred in the test groups with and without metabolic activation. No substantial increase in revertant colony numbers in of any of the five tester strains was observed following treatment with the test substance either in the presence or absence of S9 mix. Under the conditions of the test, the substance was found to be non-mutagenic (Sokolowski A, 2006).

An in vitro guideline study was performed to investigate the potential of the read-across substance C16 TMAC (25% purity) to induce gene mutations at the HPRT locus in V79 cells of Chinese hamster. All reference mutagens used as positive controls showed a distinct increase in the induced mutant colonies, thus indicating the sensitivity of the assay and the efficacy of the S9 mix. Test substance did not induce any substantial and reproducible dose dependent increase of the mutation frequency at the HPRT locus, both with and without metabolic activation. Under the test conditions, the test substance was considered to be non-mutagenic both with and without metabolic activation (Wollny H, 2007).

An in vitro guideline study was conducted to investigate the potential of the read-across substance C16 TMAC (26% purity) t to induce chromosome aberrations in V79 cells of Chinese hamster lung cells. The concentration range of the test substance was determined in a pre-experiment using the plating efficiency assay as an indicator for toxicity response. Treatment with 3.0 µg/mL and 10.0 µg/mL totally reduced the plating efficiency of the V79 cells. The mitotic index was reduced after treatment with the highest concentration at each fixation interval in the presence and absence of S9 mix. Positive controls showed distinct increases in cells with structural chromosome aberrations. There was no relevant increase in cells with structural aberrations after treatment with the test substance at any fixation interval either without or with metabolic activation by S9 mix. Under the experimental conditions, the test substance did not induce structural chromosome aberrations (Heidemann A, 1989).

In vivo

Data waiving since the read-across substance C16 TMAC was negative inin vitroassays (i.e., bacterial and mammalian mutagenicity assays as well as chromosome aberration assay). Therefore in vivo mutagenicity test is not required.


Justification for selection of genetic toxicity endpoint
No study was selected, since all the in vitro studies were negative with the structurally similar test substance C16 TMAC

Short description of key information:
C16-C18 TMAC was non-mutagenic in S. typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and E. coli strain WP2 uvrA in the reverse mutation assay. C16 TMAC did not induce gene mutations in the HPRT locus in V79 Chinese hamster cells, either in the presence or absence of metabolic activation. Moreover, the number of chromosomal aberrations was not increased after exposure to C16 TMAC in the V79 Chinese hamster cell line. Therefore, C16 TMAC is considered non-genotoxic.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the available data, no classification is required for genotoxicity according to EC (67/548/EEC) and CLP (EC 1272/2008) criteria.