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 all strains tested (OECD TG 471) (MHLW, 2005).


Cytogenicity in mammalian cells: positive in CHL/IU cells with activation (OECD TG 473) (MHLW, 2005).


Mutagenicity in mammalian cells: negative in CHO cells (OECD TG 476) (Hüls AG, 1996b).

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

Genetic toxicity in vivo

Description of key information

Micronucleus assay in mouse (ip administration): Negative (OECD TG 474) (BRRC, 1985).

Comet assay in mouse (nose-only inhalation): Negative (OECD TG 489) (Charles River 2018).

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

Additional information

Information is available from reliable studies for all the required in vitro endpoints. Where there was more than one result for an endpoint the most reliable study available was chosen as key study. Negative results were obtained in all bacterial and mammalian mutagenicity assays. Positive results were obtained with activation in both the cytogenicity studies available. A negative result was obtained in an in vivo micronucleus assay.

Trimethoxy(vinyl)silane has been tested in a valid study according to OECD TG 471 and under GLP, using the preincubation method (MHLW 2005). No increase in the number of revertants was observed in any of S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2 at any concentration up to 5000 µg/plate with or without metabolic activation. Appropriate positive and solvent controls were included and gave expected results. The results of the repeat experiment agreed with those of the first experiment. It is concluded that the test substance is negative for the induction of mutations under the conditions of the test. The result is supported by negative results in another study of bacteria mutagenicity (Hüls AG, 1996a)

Trimethoxy(vinyl)silane has been tested according to OECD TG 473 and under GLP for the induction of chromosome aberrations in mammalian cells (MHLW 2005). The test substance produced a dose related increase in chromosome aberrations in the presence of metabolic activation. No induction of polyploidy was observed. Appropriate positive and solvent controls were included and gave expected results. It is concluded that the test substance is positive for the induction of chromosome aberrations in Chinese hamster lung cells under the conditions of this test. The reviewer has seen a detailed summary in English, but has not seen the full Japanese study report. A similar result was obtained in the supporting study in which trimethoxy(vinyl)silane produced significant dose dependent increases in chromosome aberrations in the presence of metabolic activation in Chinese hamster ovary cells, and less significant increases in the absence of metabolic activation (BRRC 1985). It was concluded that the test substance is positive for the induction of chromosome aberrations in mammalian cells under the conditions of the test.

Trimethoxy(vinyl)silane has been tested in a valid study according to OECD TG 476 and under GLP (Hüls AG, 1996b). No statistically significant dose related increases in the number of revertants was observed either with or without activation. It is concluded that the test substance is negative for mutagenicity to mammalian cells under the conditions of the study.

Trimethoxy(vinyl)silane has been tested in a reliable and valid micronucleus assay according to a protocol that is similar to the current OECD TG 474 and under GLP (BRRC, 1985). No statistically significant increase in the frequency of micronucleated polychromatic erythrocytes was observed in peripheral erythrocytes of mice treated with the test substance by ip injection. Systemic toxicity was demonstrated, indicating the test substance and/or hydrolysis products were systemically available and therefore able to reach the bone marrow. There was indication of slight toxicity to bone marrow at the highest dose in female mice, which is evidence that the test substance had reached the target cells. It is concluded that trimethoxy(vinyl)silane is negative for the induction of micronuclei under the conditions of this test. Trimethoxy(vinyl)silane hydrolyses rapidly at physiological pH (half-life of 0.1 hours) and this is the main breakdown process the substance would undergo, so it is considered that the ip route would have resulted in exposure to relevant substance-related products.

Trimethoxy(vinyl)silane has been tested in a reliable and valid comet assay according to the appropriate OECD 489 Test Guideline and in compliance with GLP. No statistically significant increase in the mean percentage of DNA tails was observed in liver, lungs or bone marrow tissues of mice treated with the test substance by nose-only inhalation. Positive, negative and solvent control groups were included and gave the expected results. It is concluded that trimethoxy(vinyl)silane is negative for the induction of DNA damage under the conditions of this test (Charles River 2018).


Justification for classification or non-classification

The available information for the substance indicates that when tested in vitro, trimethoxy(vinyl)silane (CAS number 2768 -02 -7) does not induce mutations in bacterial or mammalian cells. The substance does cause chromosomal aberrations in vitro in the presence of metabolic activation, but this potential for genetic toxicity was not confirmed in in vivo studies, so it is concluded that trimethoxy(vinyl)silane is not genotoxic.

Based on the available data, trimethoxy(vinyl)silane does not require classification for genetic toxicity according to Regulation (EC) No 1272/2008.