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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
120.6 mg/m³
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
By inhalation
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
75
Dose descriptor starting point:
NOAEC
Value:
18 000 mg/m³
Modified dose descriptor starting point:
NOAEC
Value:
9 045 mg/m³
Explanation for the modification of the dose descriptor starting point:

The following correction was made to the NOAEC (inhalation): Correction for experimental exposure duration (6 h/d to 8 h/d), Correction for respiratory volume (worker): 6.7 m3/10 m3. Therefore, the corrected NOAEC for repeated-dose systemic effects via the inhalation route is: 18 000*(6 h/ 8 h) *(6.7 m3/10 m3) = 9045 mg/ m3.

AF for dose response relationship:
1
Justification:
Default
AF for differences in duration of exposure:
6
Justification:
Default (subacute to chronic)
AF for interspecies differences (allometric scaling):
1
Justification:
Default (inhalation rat to inhalation human)
AF for other interspecies differences:
2.5
Justification:
Default
AF for intraspecies differences:
5
Justification:
Default
AF for the quality of the whole database:
1
Justification:
Guideline study in compliance with GLP
AF for remaining uncertainties:
1
Justification:
Default
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

In the absence of any indication of adverse effects for any endpoint, tetramethylsilane is not classified as hazardous for human health, and it is not possible to quantify any DNELs for this substance. However, to support the exposure based waiving arguments for long-term mammalian toxicity testing, it is necessary to include semi-quantitative risk characterisation.

To facilitate this, the result of the existing OECD 422 inhalation study in rats is used to determine an indicative ‘worst-case’ no effect level for humans using the ECHA REACH guidance methodology for DNEL calculation. Only the inhalation route needs to be considered since the high volatility of tetramethylsilane (vapour pressure of 79500 Pa at 20°C) means that in the unlikely event of direct dermal exposure, the substance would evaporate rapidly from the skin surface. Exposure to consumers is not relevant for this substance, therefore only workers are considered, with the exception of man via the environment.

Tetramethylsilane is a volatile liquid which is hydrolytically stable. A combined repeat dose inhalation toxicity study and reproductive/developmental toxicity screening study was carried out in rats for tetramethylsilane according to OECD 422 and in compliance with GLP (Dow Corning Corporation, 2005, reliability score 1). There were no adverse effects on general systemic, reproductive or developmental endpoints at the highest dose tested, 5000 ppm (approx.18000 mg/m3). The NOAEC for tetramethylsilane was ≥18,000 mg/m3 in a study with rats exposed for 6 hours per day, 5 days per week.

General Population - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
21.4 mg/m³
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
By inhalation
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
150
Dose descriptor starting point:
NOAEC
Value:
18 000 mg/m³
Modified dose descriptor starting point:
NOAEC
Value:
3 214 mg/m³
Explanation for the modification of the dose descriptor starting point:

The DNEL for systemic effects via the inhaled route was determined from an inhalation study in which the NOAEC was 18000 mg/m3. The following correction was made to the NOAEC (inhalation): Correction for exposure duration (6 h/d to 24 h/d ), Correction for dosing frequency: 5 days/7 days. Therefore the corrected NOAEC for repeated-dose systemic effects via the inhalation route is: 18000*(6 h/ 24 h)* (5/7) = 3214 mg/m3.

AF for dose response relationship:
1
Justification:
Default
AF for differences in duration of exposure:
6
Justification:
Default (subacute to chronic)
AF for interspecies differences (allometric scaling):
1
Justification:
inhalation rat to inhalation human
AF for other interspecies differences:
2.5
Justification:
Default
AF for intraspecies differences:
10
Justification:
Default
AF for the quality of the whole database:
1
Justification:
Guideline study in compliance with GLP
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

Local effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
no hazard identified
Acute/short term exposure
Hazard assessment conclusion:
no hazard identified
DNEL related information

General Population - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - General Population

There is no potential for exposure to the general population via any route other than long term systemic effects via the inhalation route.