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Administrative data

Description of key information

No data about skin sensitisation is available with the trimethoxy(2,4,4 -trimethylpentyl)silane. Reliable read across data from triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3) was used.

Skin sensitisation (OECD 406 / GPMT with CAS 35435 -21 -3): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Please refer to the attached justification
Reason / purpose for cross-reference:
read-across source
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
100%
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
None
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
None
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
100%
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
None
Group:
positive control
Remarks on result:
positive indication of skin sensitisation
Remarks:
tested on regular basis in the laboratory

After intradermal injection of the test item slight erythema (grade 1) were observed in all animals.

Interpretation of results:
other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008
Conclusions:
The source substance was tested for skin sensitisation according to the OECD TG 406 (Guinea Pig Maximization Test) and in compliance with GLP. There were no signs of sensitisation recorded for any of the tested animals. Based on these findings classification for skin sensitisation according to 67/584/EEC and EC/1272/2008 is not warranted for both the source and the target substance.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

No information about skin sensitisation is available for the registered substance, however, reliable data is available for the closely related substance, triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3). The silicon-containing products of hydrolysis are close structural analogues: both trimethoxy(2,4,4-trimethylpentyl)silane (CAS 34396-03-7) and triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3) hydrolyse to (2,4,4-trimethylpentyl)silanetriol. Both substances hydrolyse very rapidly: hydrolysis is expected to occur during testing and following exposure. The further products of hydrolysis are methanol and ethanol, respectively. It is therefore considered appropriate to read-across the skin sensitisation results from triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3) to the registered substance.

Guinea Pig Maximization Test:

In the available key study (Bioservice, 2007) the test item triethoxy(2,4,4-trimethylpentyl)silane (CAS 35435-21-3) was tested for skin sensitising properties according to the OECD TG 406 and in compliance with GLP. 10 Hsd Poc: DH Guinea pigs of the test group were used for this study. During the induction phase the animals were intradermally injected with 5% test item (diluted in cotton seed oil) and, after treatment with sodium lauryl sulphate, topically treated with 100% test material. After a latency of 14 days (to allow a potential reaction with the immune system) the animals were challenged with 100% test material on the flank. The grade of skin reactions was compared to those of the 5 control animals, which were treated with cotton seed oil during the induction phase and, during the challenge phase, with the test item, respectively. The sensitisation rate after application of the test item was 0%. Under the test conditions described, the test item showed no sensitising effects. Normal weight gain as compared to both historical data and control animals was reported for the test animals. No other signs of clinical toxicity were reported.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

The available data is reliable and suitable for classification. Based on this data, classification for skin sensitisation according to 67/584/EEC and EC/1272/2008 is not warranted.