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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Key value for chemical safety assessment

Additional information

There is no information available for genetic toxicity endpoints for trichloroisobutylsilane.In vitrostudies are available for two related substances, trimethoxy(2-methylpropyl)silane (CAS 18395-30-7) and triethoxyisobutylsilane (CAS 17980-47-1). The results of all the studies were in agreement. Trichloroisobutylsilane, trimethoxy(2-methylpropyl)silane and triethoxyisobutylsilane share a common hydrolysis product, isobutylsilanetriol, although trimethoxy(2-methylpropyl)silane and triethoxyisobutylsilane will hydrolyse more slowly compared with very rapid for the registration substance. It is considered appropriate to read across the genetic toxicity results for trimethoxy(2-methylpropyl)silane and triethoxyisobutylsilane to trichloroisobutylsilane as all three substances share similar functional groups and the differences are not expected to contribute to their genetic toxicity.

Short description of key information:
In vitro:
Gene mutation (Bacterial reverse mutation assay / Ames test): read-across from analogous substance trimethoxy(2-methylpropyl)silane: negative with and without activation in all strains tested (similar to OECD TG 471)
Cytogenicity in mammalian cells: read-across from analogous substance triethoxyisobutylsilane: negative in Chinese hamster lung fibroblasts (V79) (OECD TG 473)
Mutagenicity in mammalian cells: read-across from analogous substance triethoxyisobutylsilane: negative in CHO cells (OECD TG 476)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available information on the analogous substance trimethoxy(2-methylpropyl)silane (CAS number 18395-30-7), indicates that it is not mutagenic to bacteria. Information on another analogous substance, triethoxyisobutylsilane (CAS number 17980-47-1), indicates that it is not cytogenic or mutagenic to mammalian cells. The results of all the in vitro studies were negative, so there is no justification for testing in vivo. It is therefore considered that classification for mutagenicity is not required.