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Administrative data

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Additional information

There are no adequate reproductive toxicity data on trichloro(ethyl)silane or its hydrolysis product, ethylsilanetriol, so good quality data for the related substance methyltrimethoxysilane (MTMS) has been used to assess the reproductive effects of trichloro(ethyl)silane.

Trichloro(ethyl)silane hydrolyses rapidly in contact with water (half-life <1 minute at pH 7), generating HCl and ethylsilanetriol. Methyltrimethoxysilane (MTMS, CAS 1185 -55 -3) hydrolyses more slowly at pH 7 (half-life ca. 2 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 methylsilanetriol. The silanol hydrolysis products are therefore very similar in chemical structure, the only difference being the replacement of -C2H5 with -CH3. Both have high water solubility and very low logKow(log Kow-1.9 and -2.4, respectively). They are therefore expected to have similar toxicological behaviour. Data obtained via the oral route for MTMS are therefore considered appropriate for read-across to trichloro(ethyl)silane.



Short description of key information:
No reproductive toxicity data are available for trichloro(ethyl)silane, therefore data for the related substance methyltrimethoxysilane, CAS 1185-55-3, have been read-across. No effects on reproductive parameters were observed in an OECD 422 screening study (Dow Corning, 2005) up to the highest dose tested. The NOAEL was therefore greater than or equal to 1000 mg/kg bw/day.

Effects on developmental toxicity

Description of key information
No developmental toxicity data are available for trichloro(ethyl)silane, therefore data for the related substance methyltrimethoxysilane, CAS 1185-55-3, have been read-across. No effects on reproductive parameters were observed in an OECD 422 screening study (Dow Corning, 2005) up to the highest dose tested. The NOAEL was therefore greater than or equal to 1000 mg/kg bw/day. 
Effect on developmental toxicity: via oral route
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Additional information

There are no adequte developmental toxicity data on trichloro(ethyl)silane or its hydrolysis product, ethylsilanetriol, so good quality data for the related substance methyltrimethoxysilane (MTMS) has been used to assess the developmental toxicity of trichloro(ethyl)silane.

Trichloro(ethyl)silane hydrolyses rapidly in contact with water (half-life <1 minute at pH 7), generating HCl and ethylsilanetriol. Methyltrimethoxysilane (MTMS, CAS 1185 -55 -3) hydrolyses more slowly at pH 7 (half-life ca. 2 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 methylsilanetriol. The silanol hydrolysis products are therefore very similar in chemical structure, the only difference being the replacement of -C2H5 with -CH3. Both have high water solubility and very low logKow(log Kow-1.9 and -2.4, respectively). They are therefore expected to have similar toxicological behaviour. Data obtained via the oral route for MTMS are therefore considered appropriate for read-across to trichloro(ethyl)silane.

Justification for classification or non-classification

The available read-across data on methyltrimethoxysilane do not suggest that there is a need to classify trichloro(ethyl)silane for adverse effects on reproduction or development.

Additional information