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Administrative data

Description of key information

No repeat-dose toxicity data are available for trichloro(phenyl)silane, therefore good quality data for the related substance trimethoxy(phenyl)silane have been read-across.
A well reported oral combined repeated dose/reproductive and developmental screening study (Harlan, 2009), conducted according to the current guideline and in accordance with GLP, did not identify an NOAEL for trimethoxy(phenyl)silane; effects to the urinary bladder were reported at the lowest tested dose of 100 mg/kg bw/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Dose descriptor:
LOAEL
100 mg/kg bw/day

Additional information

There are no repeated dose toxicity data on trichloro(phenyl)silane or its hydrolysis product, phenylsilanetriol, so good quality data for the related substance trimethoxy(phenyl)silane have been used to assess the general systemic toxicity of trichloro(phenyl)silane. Local effects from the other hydrolysis product (HCl) are not addressed by these data.

Trichloro(phenyl)silane hydrolyses rapidly in contact with water (half-life <1 minute at pH 7), generating HCl and phenylsilanetriol. Trimethoxy(phenyl)silane (CAS 2996 -92 -1) hydrolyses more slowly at pH 7 (half-life ca. 0.4 hours), but under acidic conditions such as in the stomach following ingestion, much more rapid hydrolysis can be expected based on experience with other methoxysilanes. The relevant hydrolysis products are methanol and phenylsilanetriol. Both parent materials therefore generate a common silanol hydrolysis product.

It is of note that the oral NOAEL in rats for methanol is greater (500 mg/kg bw/day) than the dose that is expected to be generated from hydrolysis of trimethoxy(phenyl)silane in the stomach. Therefore the effects of trimethoxy(phenyl)silane following a dose of 100 mg/kg bw/day are not thought to be attributable to methanol.


Repeated dose toxicity: via oral route - systemic effects (target organ) urogenital: kidneys; urogenital: urinary bladder

Justification for classification or non-classification

The available OECD 422 study for the related substance trimethoxy(phenyl)silane indicates that the kidney and urinary bladder are potential target organs following oral exposure. However, at the dose levels tested, corrosive effects of trichloro(phenyl)silane would outweigh any potential systemic effects. It is therefore not considered appropriate to classify trichloro(phenyl)silane for repeated dose toxicity.