Hexadecyltrimethoxysilane

Endpoint summary

Description of key information

Acute oral toxicity (OECD TG 423, GLP): LD50>2000 mg/kg bw
Acute inhalation toxicity: data waiver according to Column 2 of REACH Annex VIII
Acute dermal toxicity: data waiver according to Column 2 of REACH Annex VIII

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 April 2002 to 16 May 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Version / remarks:

(adopted 2002)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Species:

rat

Strain:

other: Crl:CD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland GmbH, Sulzfeld, GERMANY
- Age at study initiation: 41 days (m); 49 days (f)
- Weight at study initiation: 210-211 g (m); 185-199 g (f)
- Fasting period before study: 16 h
- Housing: 2-3/Makrolon cage (type III)
- Diet: standard diet ad libitum
- Water: drinking water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22±3
- Humidity (%): 55±15
- Air changes (per hr): not stated
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

VEHICLE
none

MAXIMUM DOSE VOLUME APPLIED: 2.25 ml/kg bw

CLASS METHOD
- Rationale for the selection of the starting dose: none identified within report, but follows guideline which recommends a starting dose of 2000 mg/kg bw.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations 5, 15, 30, 60 mins; 3, 6, 24 h; then daily for 14 days. Weighings weekly.
- Necropsy of survivors performed: yes

Statistics:

None.

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality was observed throughout the study period.

Clinical signs:

other: No clinical signs were observed in the animals during the study.

Gross pathology:

No significant findings.

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

A reliable study (reliability score 1) conducted according to the standard guideline for the Acute Toxic Class method and in compliance with GLP found the LD50 in rats to be in excess of 2000 mg/kg bw. There were no clinical signs of toxicity, effects on body weight or macroscopic findings.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate and reliable study, and is thus sufficient to fulfil the standard information requirements set out in Annex VII, 8.5, of Regulation (EC) No 1907/2006.

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (e.g. skin irritation, skin sensitisation)

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute toxicity: oral

In the key acute oral toxicity study (LPT, 2002a), conducted according to OECD TG 423 (Acute Toxic Class Method) and in compliance with GLP, undiluted hexadecyl(trimethoxy)silane (CAS 16415-12-6) was administered via gavage to 3 Crl:CD rats per sex at a dose of 2000 mg/kg bw. No deaths occurred and no clinical signs were observed throughout the study period. Among this, no treatment-related effects on body weight were noted. Gross pathology revealed no significant findings. The LD50 was therefore set at > 2000 mg/kg bw.

These results were supported by an acute oral toxicity study, conducted according to OECD TG 401 and in compliance with GLP (Asta Pharma AG, 1989a). The oral gavage administration of the registered substance at a dose 5002 mg/kg bw to 5 Bor:WISW (SPFCpb) rats of each sex did not result in deaths. No clinical signs and no treatment-related effects on body weight or abnormalities on gross macroscopic examination were observed. Thus, a LD50 > 5002 mg/kg bw was deduced.

Acute toxicity: inhalation

No data available.

Acute toxicity: dermal

The study does not need to be conducted because the substance does not meet the criteria for classification as acute toxicity or STOT SE by the oral route and no systemic effects have been observed in in vivo studies with dermal exposure (skin irritation and skin sensitisation).

As supporting information, available acute dermal toxicity data from the source substance trimethoxy(octadecyl)silane (CAS 3069-42-9) was considered in accordance with Regulation (EC) No. 1907/2006 Annex XI, 1.5 “Grouping of substances and read across”.

Trimethoxy(octadecyl)silane (CAS 3069-42-9) was investigated for acute dermal toxicity in a limit test conducted according to the OECD TG 402, and in compliance with GLP (Degussa AG, 1987). 2000 mg/kg bw of the undiluted test material were occlusively applied to the shoulder of 3 White Russian rabbits per sex. Following 24 h of exposure, the test material was washed off with water. No deaths occurred throughout the study period, and no clinical signs except for local effects (described as erythema on the test site immediately after treatment and desquamation on days 3 -7 days of the observation period) were observed. All effects were fully reversible within 13 days. Among this, no effects on body weight gain and no abnormal pathological findings were reported. Based on this data, the LD50 for acute dermal toxicity of trimethoxy(octadecyl)silane (CAS 3069-42-9) was set at > 2000 mg/kg bw.

Justification for classification or non-classification

The available data is reliable and suitable for classification. Based on this data, classification for acute toxicity according to Regulation (EC) No. 1272/2008 is not warranted.