Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
6.6 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
Modified dose descriptor starting point:
NOAEC
DNEL value:
494 mg/m³
Explanation for the modification of the dose descriptor starting point:

DNEL for systemic effects via the inhalation route is derived from the rat 28-day inhalation study in which the NOAEC was 984 mg/m3. Correction for exposure duration and respiratory rate and volume (rat to human worker): (6h/8h)*(6.7m3/d/10m3/d) (default). Therefore the corrected NOAEC for repeated-dose systemic effects via the inhalation route is [984 mg/m3*(6h/8h)*(6.7m3/d/10m3/d)] = 494 mg/m3

AF for dose response relationship:
1
Justification:
The starting point is the NOAEC which was the low dose. There was a dose response in incidence and severity of effects noted.
AF for differences in duration of exposure:
6
Justification:
Subacute to chronic (default)
AF for interspecies differences (allometric scaling):
1
Justification:
Inhaled rat to inhaled human (default)
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:
Good quality guideline, GLP study
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
6.6 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
DNEL extrapolated from long term DNEL

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:
DNEL (Derived No Effect Level)
Value:
0.93 mg/kg bw/day
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):
300
Modified dose descriptor starting point:
NOAEL
DNEL value:
280 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

DNEL for systemic effects via the dermal route is derived from the rat 28-day inhalation study in which the NOAEC was 984 mg/m3. Correction for exposure duration (rat to human worker) and respiratory volume (default rat, 8 hour): (6h/8h)*(0.38m3/kg)). Therefore the corrected NOAEC for repeated-dose systemic effects via the dermal route is [984 mg/m3*(6h/8h)*(0.38m3/kg)] = 280 mg/kg bw/day

AF for dose response relationship:
1
Justification:
The starting point is the NOAEC which was the low dose. There was a dose response in incidence and severity of effects noted.
AF for differences in duration of exposure:
6
Justification:
Subchronic to chronic (default)
AF for interspecies differences (allometric scaling):
4
Justification:
inhaled rat to dermal human (default)
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:
Good quality guideline, GLP study
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
Acute/short term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
0.93 mg/kg bw/day
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):
300
DNEL extrapolated from long term DNEL

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

Short-term high exposures are considered unlikely given the high levels of control in place at sites producing and using the substance. DNELs for long-term exposure are therefore adequate to protect against short-term exposures and no separate short-term DNELs are calculated.

General Population - Hazard via inhalation 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
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:
DNEL (Derived No Effect Level)
Value:
0.058 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
Route of original study:
Oral
DNEL related information
DNEL derivation method:
ECHA REACH Guidance
Overall assessment factor (AF):
600
Modified dose descriptor starting point:
NOAEL
DNEL value:
34.55 mg/kg bw/day
Explanation for the modification of the dose descriptor starting point:

The DNEL for systemic effects via the oral route is determined on the basis of the NOAEL of trimethoxymethylsilane in the 28-day rat oral study. However, the effects noted were considered most likely to be due to the hydrolysis product, methylsilanetriol, which because of it's lower molecular weight, the NOAEL was corrected as follows: Methylsilanetriol molecualr weight/trimethoxymethylsilane molecular weight * NOAEL dose = 94.14/136.22*50 = 34.55 mg/kg/day.

AF for dose response relationship:
1
Justification:
The starting point is the NOAEL which was an intermediate dose. There was a dose response in incidence and severity of effects noted.
AF for differences in duration of exposure:
6
Justification:
Subchronic to chronic (default)
AF for interspecies differences (allometric scaling):
4
Justification:
Oral rat to oral human (default)
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:
Good quality guideline, GLP study
AF for remaining uncertainties:
1
Justification:
No remaining uncertainties
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