Registration Dossier

Administrative data

Workers - Hazard via inhalation route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
68 mg/m³
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
6
Modified dose descriptor starting point:
NOAEC
Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

Workers - Hazard via dermal route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
9.7 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
6
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

Workers - Hazard for the eyes

Additional information - workers

3-Chloropropyltrimethoxysilane is a volatile liquid which hydrolyses (half-life 3.1 hour at pH 7 in an OECD 111 study) in moist air and in contact with tissues to form methanol and 3-chloropropylsilanetriol.

 

There are several reliability score 1 studies for repeated inhalation of (3-chloropropyl)trimethoxysilane. The 90-day study was selected as the key study as it tested over the longest duration.

In the key 90-day inhalation study, microscopic examinations did not reveal any adverse findings in females exposed to 0.5 or 5 ppm. Eight of 10 male animals in the 0.5 ppm exposure group were reported as normal. The two remaining male animals exhibited minimal chronic cystitis of the urinary bladder. Nine of 10 male animals were reported as normal in the 5.0 ppm exposure group. The remaining male animals exhibited minimal chronic cystitis of the urinary bladder. Treatment-related histopathologic effects were observed in the 100 ppm group animals. Increased incidence of hyperplasia of the urinary bladder epithelium was noted in both sexes of this group.

It is not known whether the urinary bladder was inflated by a fixative before microscopic examination. Without inflation of the urinary bladder the relevance of the hyperplasia is questionable. Based onthe fact that the hyperplasia of the bladder was mild /minimal and in some cases associated with a minimal inflammation (cystitis) it can presumed that if the stimulus for the hyperplastic changes is removed the hyperplasia will resolve within a matter of weeks and the urinary bladder will return to a normal histological appearance.A minimal/mild change of the urinary bladder not associated with any clinical symptoms or changes in urine parameters does not reflect a marked organ dysfunction. Therefore, the mild/minimal hyperplastic effects are not considered as adverse and the NOAEC is 100 ppm(813 mg/m3).

There are no data for the oral and dermal routes.

3-Chloropropyltrimethoxysilanewas tested in an inhalation OECD 422 study (Marburger, A., 2005), whole-body in rats, up to and including the highest concentration of 100 ppm. In this study there were no signs of adverse effects on reproduction or development parameters. The upper dose level was selected on the basis of the adverse findings at higher exposure concentrations in the 90-day study summarised above. Therefore based on these results the NOAEC was established to be at least 100 ppm (813 mg/m3) for these endpoints. Test animals were exposed for 6 hours per day, 7 days per week.

No significant effects were observed up to the maximum dose tested in an OECD 422 reproductive and developmental toxicity screening test in rats. It is therefore not possible to quantify DNELs for reproductive or developmental endpoints.

No quantitative DN(M)ELs could be derived for:

Acute toxicity – local effects (no effects)

Long-term toxicity – local effects (no effects)

Reproductive/developmental toxicity – no effects

Mutagenicity (not mutagenic)

Carcinogenicity (no data)

In the absence of any significant findings relating to reproductive or developmental endpoints in appropriate screening tests, the critical health effect is considered to be repeated-dose toxicity. 3-chloropropyltrimethoxysilane is not classified as irritant, mutagenic, carcinogenic or sensitising.

The DNELs used for risk characterisation (workers) are therefore:

DNEL (long-term, inhalation): 68 mg/m3

DNEL (long-term, dermal): 9.7 mg/kg/day

General Population - Hazard via inhalation route

Systemic effects

Acute/short term exposure
DNEL related information

Local effects

Acute/short term exposure
DNEL related information

General Population - Hazard via dermal route

Systemic effects

Acute/short term exposure
DNEL related information

General Population - Hazard via oral route

Systemic effects

Long term exposure
Hazard assessment conclusion:
DNEL (Derived No Effect Level)
Value:
4.2 mg/kg bw/day
Most sensitive endpoint:
repeated dose toxicity
DNEL related information
Overall assessment factor (AF):
10
Modified dose descriptor starting point:
NOAEL
Acute/short term exposure
DNEL related information

General Population - Hazard for the eyes

Additional information - General Population

No exposure of consumers will occur during normal handling and use therefore DNELs via the dermal and inhalation routes are not calculated for consumers. An oral DNEL for the general population is needed for risk characterisation for indirect exposure via the environment.

The DNEL is based on the data discussed above for workers.

The DNEL used for risk characterisation (consumers) is DNEL (long-term, oral): 4.2 mg/kg/day