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:
Default for sub-chronic to chronic
AF for interspecies differences (allometric scaling):
1
Justification:
Not required for inhalation route
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 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:
70.1 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:
Default from sub-chronic to chronic
AF for interspecies differences (allometric scaling):
4
Justification:
Default rat to 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:
Good quality guideline 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):
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

Workers - Hazard for the eyes

Local effects

Hazard assessment conclusion:
no hazard identified

Additional information - workers

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 its 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:
Default from sub-chronic to chronic
AF for interspecies differences (allometric scaling):
4
Justification:
Default rat to 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:
Good quality guideline 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