Registration Dossier

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

There are no skin sensitisation data on tetramethyl orthosilicate, so good quality data on the structurally-related substance, tetraethyl orthosilicate have been used for read-across.

In the absence of measured data for tetramethyl orthosilicate, it is considered appropriate to use this result in support of the skin sensitisation endpoint. The read-across substance is moderately lipophilic (log Kow 3.0) for which dermal uptake is favourable. The registered substance is hydrophilic (log Kow -0.5), therefore the read-across substance represents a worst-case with respect to potential for dermal absorption. After uptake both substances hydrolyse rapidly with half-lives of ca. 1 minute (tetramethyl orthosilicate) and 2.5 hours (tetraethyl orthosilicate) at pH 7 and 37.5°C, forming methanol or ethanol and silicic acid. Neither methanol nor ethanol is sensitising to skin (OECD, 2004a, OECD 2004b), therefore read-across based on the common hydrolysis product is relevant.


Migrated from Short description of key information:
There are no skin sensitisation data on tetramethyl orthosilicate, so good quality data on the structurally-related substance, tetraethyl orthosilicate have been read-across.

In a skin sensitisation study (Buehler test) conducted to OECD 406 (except only ten test animals and no positive control) DYNASIL A (tetraethyl orthosilicate) was not sensitising to the skin of guinea-pigs (Degussa-Huls, 1992).

Justification for selection of skin sensitisation endpoint:
The selected study is the only skin sensitisation study available for a relevant surrogate substance. It was conducted in accordance with an appropriate OECD test guideline and in compliance with GLP.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

Based on read-across data on tetraethyl orthosilicate, tetramethyl orthosilicate is not classified as a skin sensitiser according to Regulation (EC) No 1272/2008.