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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Endpoint summary

Administrative data

Description of key information

Additional information

Reliable acute toxicity tests results are available for freshwater fish (Oncorhynchus mykiss), invertebrates (Daphnia magna) and algae (Pseudokirchneriella subcapitata).


The hydrolysis rate of trimethoxysilane (CAS 2487-90-3) (half-lives of =0.2 minutes at pH 4 and pH 9, =0.3 minutes at pH 7 and 2°C) and test media preparation methods (overnight mixing of test solutions and static regime) mean it is likely that the test organisms in each test were exposed primarily to the hydrolysis products, monosilicic acid and methanol.

The relevant short-term values are:

Fish: LC50 (96 h): >100 mg/L (nominal) (Springborn Smithers, 2004a).

Invertebrates: Daphnia: EC50 (48 h): >100 mg/L (nominal) (Springborn Smithers, 2004b).

Algae: ErC50 (72 h): >100 mg/L and NOEC <6.3 mg/L (nominal) (Springborn Smithers, 2004c).