Registration Dossier

Administrative data

Description of key information

The key studies for skin and eye irritation were in vivo studies conducted in accordance with the appropriate test guidelines and GLP (Hazelton Labs, 1992 and Hoescht, 1991). Trimethoxy(methyl)silane was not irritant to rabbit skin or eyes, although mild effects were observed.

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The key studies for skin and eye irritation were selected as the best available guideline studies, performed in compliance with GLP, and hence assigned Reliability 1.

The key study for skin irritation found the test material not irritating to rabbit skin in a test conducted in accordance with OECD 404 and in compliance with GLP (Hazleton, 1992). The study reports a mean erythema score (24/48/72 hours) of 0.11, with all effects fully reversible. A mean oedema score of 0 was also reported.

A supporting study for skin irritation was also available for review (Hazelton labs, 1966) which reports a primary dermal irritation index value of 0.66 in a study that was similar to OECD 404 with intact and abraded skin. The skin reactions observed do not meet the criteria for classification as a skin irritant in the EU.

A third study on skin irritation is also available, (Mellon Institute, 1963) in which the results were consistent with the other studies.

The key study for eye irritation found the test material non-irritating to the eyes of rabbits, in a study conducted in accordance with OECD 405 and in compliance with GLP (Hoechst, 1991). Mild to moderate conjunctival redness and discharge were observed in all test animals 1 hour post-instillation. Mild chemosis was also observed at this time point. All effects were fully resolved by the 24-hour observation.

A supporting study by the Mellon Institute (1963) was also available, reporting Grade 2 corneal necrosis determined according to a protocol which was lacking in detail on the study conduct, and was not compliant with GLP, using an excess amount of test material.

A second supporting study found the test substance slightly irritating in a reliable study conducted according to an appropriate test protocol, but not compliant with GLP (Hazelton Labs, 1966). The observed effects do not meet the criteria for classification as an eye irritant in the EU.

Finally, a reliability 4 supporting study was also available

which found the test material slightly irritating, but which does not meet current guideline requirements (Laboratoires de Recherches de la Societe des Usines Chimiques Rhone-Poulenc, 1972). The result does, however, add to the weight of evidence for eye irritation. The observed effects do not meet the criteria for classification as an eye irritant in the EU.


Justification for classification or non-classification

Based on the available data trimethoxy(methyl)silane does not require classification for irritation according to Regulation (EC) No 1272/2008.