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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Long-term toxicity to fish

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Administrative data

Link to relevant study record(s)

fish early-life stage toxicity
Data waiving:
exposure considerations
Justification for data waiving:
Justification for type of information:
For detailed information on this adaptation based on Annex XI (Section 3), please refer to the CSR attached in Section 13.

Description of key information

A long-term toxicity study on fish is not necessary as

- exposure considerations in accordance with Annex XI, Section 3, indicate that exposure of aquatic organisms to trimethoxyphenylsilane is absent or not significant


- the substance has a low hazard potential based on the available toxicity data.

Key value for chemical safety assessment

Additional information

In accordance with Annex XI, Section 3, exposure of aquatic organisms to trimethoxyphenylsilane (CAS No. 2996-92-1) is absent or not significant. 

The environmental hazard assessment, PNEC derivation and risk characterization is based on the silanol hydrolysis product, phenylsilanetriol, as the substance hydrolyses rapidly. The other hydrolysis product, methanol, is known for its absence of environmental toxicity.

The hazard assessment showed no short-term aquatic hazard to all three trophic levels (all acute effect values > 100 mg/L). Consequently, no PNECs aqua (freshwater/marine water) were derived. The silanol hydrolysis product is well soluble. Significant deviations from this overall ecotoxicity profile are not expected and greater long-term toxicity in an additional test with fish is considered unlikely.

However, for the purpose of exposure-based adaptation as in the present endpoint, PNECs were derived in the Chemical Safety Report (CSR, Chapters 9 and 10) for the required risk characterization even though no hazard was identified in the available aquatic toxicity studies. The PNECs aqua (freshwater/marine water) were derived using a worst-case threshold value of 100 mg/L in combination with the standard assessment factors of 1000 and 10000, respectively, as outlined in ECHA guidance R.10 (2008).

The risk characterization for the silanol hydrolysis product of the substance indicated no risk to the aquatic environment (RCR < < 1).

For detailed information on the risk assessment please refer to the attached documentation in Section 13.