Triethylsilane

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No measured reproductive toxicity data are available for the registration substance therefore this endpoint is filled by read-across from data on the structural analogue, tetramethylsilane (CAS 75-76-3).

In the key repeated dose inhalation study conducted according to OECD 422 study and in compliance with GLP (Dow Corning Corporation, 2005), whole body exposure of rats to tetramethylsilane did not result in any adverse effects on reproductive parameters that could be attributed to treatment. Therefore, the NOAEC for reproductive toxicity was considered to be at least 5000 ppm (the highest concentration tested), which is equivalent to approximately 24000 mg/m³.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

24 000 mg/m³

Study duration:

subacute

Species:

rat

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

There are no reproductive toxicity data on triethylsilane via any route of exposure. Therefore data on the structurally similar substance tetramethylsilane (CAS 75-76-3) have been read across for toxicity to reproduction.

The key 28-day combined repeated dose inhalation toxicity study and reproductive/developmental toxicity screening study was carried out for tetramethylsilane according to OECD 422 (1996) and in compliance with GLP (Dow Corning Corporation, 2005). Groups of 10 male and 10 female Sprague-Dawley rats were exposed by whole-body inhalation to vapour at 0, 200, 1000 and 5000 ppm for six hours a day, seven days a week for up to 46 consecutive days. Males and toxicity group females were treated for 28 and 29 days respectively. Reproductive group females were treated for 14 days prior to the mating period, during the mating period then up to and including gestation day 19. There were no adverse effects on reproductive toxicity endpoints at the highest dose tested, 5000 ppm (ca. 24000 mg/m³). No effects on sperm or reproductive parameters were observed.

Read-across hypothesis

The read across hypothesis is that triethylsilane and tetramethylsilane are both hydrolytically stable, and are structurally similar with similar physicochemical properties. Acute toxicity data available for triethylsilane, and repeated dose toxicity data available for tetramethylsilane and the methyl analogue of the registered substance, trimethylsilane (CAS 993-07-7) show similar lack of systemic toxicity.

See Section 'repeated dose toxicity' for further justification of the read-across.

Effects on developmental toxicity

Description of key information

No measured developmental toxicity data are available for the registration substance therefore this endpoint is filled by read-across from data on the structural analogue, tetramethylsilane (CAS 75-76-3).

In the key repeated dose inhalation study conducted according to OECD 422 study and in compliance with GLP (Dow Corning Corporation, 2005), whole body exposure of rats to tetramethylsilane did not result in any adverse effects on developmental parameters that could be attributed to treatment. Therefore, the NOAEC for developmental toxicity was considered to be at least 5000 ppm (the highest concentration tested), which is equivalent to approximately 24000 mg/m³.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

24 000 mg/m³

Study duration:

subacute

Species:

rat

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

There are no developmental toxicity data on triethylsilane via any route of exposure. Therefore data on the structurally similar substance tetramethylsilane (CAS 75-76-3) have been read across for developmental toxicity.

The key 28-day combined repeated dose inhalation toxicity study and reproductive/developmental toxicity screening study was carried out for tetramethylsilane according to OECD 422 (1996) and in compliance with GLP (Dow Corning Corporation, 2005). Groups of 10 male and 10 female Sprague-Dawley rats were exposed by whole-body inhalation to vapour at 0, 200, 1000 and 5000 ppm for six hours a day, seven days a week for up to 46 consecutive days. Males and toxicity group females were treated for 28 and 29 days respectively. Reproductive group females were treated for 14 days prior to the mating period, during the mating period then up to and including gestation day 19.

There were no adverse effects on developmental toxicity endpoints at the highest dose tested, 5000 ppm (ca. 24000 mg/m³). No effects on pup body weights or pup survival were observed.

Read-across hypothesis

The read across hypothesis is that triethylsilane and tetramethylsilane are both hydrolytically stable, and are structurally similar with similar physicochemical properties. Acute toxicity data available for triethylsilane, and repeated dose toxicity data available for tetramethylsilane and the methyl analogue of the registered substance, trimethylsilane (CAS 993-07-7) show similar lack of systemic toxicity.

See Section 'repeated dose toxicity' for further justification of the read-across.

Justification for classification or non-classification

Based on the available data on tetramethylsilane, triethylsilane does not require classification for reproductive toxicity according to Regulation (EC) No 1272/2008.