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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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Diss Factsheets

Administrative data

Key value for chemical safety assessment

Additional information

Information is available from reliable studies for in vitro mutagenicity to bacteria. There is no information available for other in vitro or in vivo genetic toxicity endpoints for Trichloro(2,4,4-trimethylpentyl)silane. In vitro and in vivo cytogenicity studies are, however, available for the related substance Triethoxy(2,4,4 -trimethylpentyl)silane (CAS 35435 -21 -3). Triethoxy(2,4,4 -trimethylpentyl)silane and Trichloro(2,4,4-trimethylpentyl)silane share a common hydrolysis product, (2,4,4-trimethylpentyl)silanetriol, although Triethoxy(2,4,4-trimethylpentyl)silane will hydrolyse more slowly (half life ca. 22 h (predicted)) compared with very rapid for the trichloro analogue. It is considered appropriate to read across the genetic toxicity results for Triethoxy(2,4,4-trimethylpentyl)silane because (2,4,4-trimethylpentyl)silanetriol and Triethoxy(2,4,4-trimethylpentyl)silane have similar functional groups, and the differences are not expected to contribute to their genetic toxicity. In addition, there is data for other triethoxy silanes and these show no evidence of genetic toxicity imparted by the ethoxy groups.

Short description of key information:
In vitro:
Gene mutation (Bacterial reverse mutation assay / Ames test): negative with and without activation in all strains tested (OECD TG 471)
Cytogenicity in mammalian cells: negative in Chinese lung fibroblasts (OECD TG 473) read-across from analogous substance CAS 34534-21-3

In vivo
Micronucleus assay oral study in mouse: read-across from analogous substance CAS 34534-21-3: Negative (OECD TG 474)

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The available information for the substance indicates that when tested in vitro, Trichloro(2,4,4-trimethylpentyl)silane (CAS number 18379 -25 -4) does not induce mutations in bacterial cells. The analogous substance, Triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435 -21 -3),

did not induce mutations in bacterial cells, nor chromosome aberrations in mammalian cells. The conclusion reached from the in vitro results is confirmed by the negative result obtained when the analogous substance was tested in vivo in the mouse micronucleus assay. Therefore it is considered that classification for mutagenicity is not required.