Registration Dossier

Administrative data

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Gene mutation (Bacterial reverse mutation assay / Ames test): negative with and without activation in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 Escherichia coli WP2 uvrA (OECD TG 471) (Wagner and Dakoulas (2001)).

Cytogenicity in mammalian cells: negative with and without metabolic activation in Chinese hamster V79 cells (OECD 473) (Oppong-Nketiah, M., (2012)).

Mutagenicity in mammalian cells: positive without metabolic activation in L5178Y mouse lymphoma cells (OECD TG 476) (Trenz, K (2012)).

Endpoint conclusion
Endpoint conclusion:
adverse effect observed (positive)

Genetic toxicity in vivo

Description of key information

An in vivo study is proposed to follow up the positive result in the mammalian mutagenicity study.

Endpoint conclusion
Endpoint conclusion:
no study available (further information necessary)

Additional information

3-(triethoxysilyl)propanethiol has been tested for mutagenicity to bacteria in a study which was conducted according to OECD 471, compliant with GLP (Wagner and Dakoulas (2001)). No evidence of a test substance related increase in the number of revertants was observed with or without activation in the initial or the repeat experiments. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.

The potential for induction of damage to chromosomes in mammalian cells was investigated by testing 3-(triethoxysilyl)propanethiol in a study conducted according to OECD 473 and under GLP (Oppong-Nketiah (2012)). No evidence for the induction of structural or numerical chromosome aberrations was observed when the substance was tested up to cytotoxic concentrations with and without metabolic activation. Appropriate solvent and positive controls were included and gave expected results. It is concluded that the substance is not clastogenic or aneugenic (does not induce structural or numerical chromosome aberrations) under the conditions of the test.

3-(triethoxysilyl)propanethiol has been tested for mutagenicity to mammalian cells (thymidine kinase locus) in a reliable study conducted according to OECD 476 and under GLP (Trenz, K (2012)). An increase in the mutant frequency was observed in mouse lymphoma L5178Y cells in the absence of metabolic activation. In addition, an increase in the number of small colonies was observed without metabolic activation, suggesting a clastogenic effect. The test substance is considered to be mutagenic without metabolic activation under the conditions of the study.

It is proposed that the evidence for mutagenicity to mammalian cells be investigated in an in vivo micronucleus study.





Justification for classification or non-classification

Results from an in vitro mammalian cell gene mutation assay indicated potential for mutagenicity, so in vivo testing is proposed.