Registration Dossier

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

No data are available for the registered substance. However short-term toxicity data are available for the structurally analogous substance tetraethyl orthosilicate (CAS 78-10-4), which shares the same silanol hydrolysis product as the registered substance, silicic acid. 

LC50, Fish: >245 mg/l

EC50, Invertebrates: >75 mg/l

EC50, Algae: >100 mg/l (based on nominal concentrations, >22 mg/l based on mean measured concentrations of the test substance).

The rapid hydrolysis of tetramethyl orthosilicate means that it is appropriate to base PNECderivation on the basis of data for its hydrolysis products. This approach was also adopted for tetraethyl orthosilicate. The read-across data for tetraethyl orthosilicate indicate that the common hydrolysis product, silicic acid, is not toxic at the loading rates used.

For the other hydrolysis product, methanol, short-term aquatic toxicity data for methanol reviewed under the OECD SIDS programme indicate that L(E)C50 values for fish, invertebrates and algae exposed are all ≥10 000 mg/l. The low toxicity of methanol to aquatic organisms is confirmed by QSAR predictions for short-term L(E)C50 values of >1000 mg/l for the same three taxonomic groups with a lowest 96-hour EC50 value of 5000 mg/l reported for algae. There are no long-term data for methanol. However, methanol is readily biodegradable and therefore unlikely to be of concern for long-term effects in the aquatic environment.