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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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
Type of information:
experimental study planned (based on read-across)
Study period:
After approval by ECHA
Justification for type of information:
Please see the RAAF report for ecotoxicity attached in the IUCLID EPSR, Section 13 of IUCLID and Annex 4 of the CSR for justification of read-across.
according to guideline
OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)
Principles of method if other than guideline:
Not applicable

Description of key information

Key value for chemical safety assessment

Additional information

No measured long-term toxicity to fish data are available with the registered substance, 3-(trimethoxysilyl)propane-1-thiol (CAS 4420-74-0, EC No. 224-588-5).

Long-term aquatic toxicity testing with the analogue substance 3-(triethoxysilyl)propanethiol (CAS 14814-09-6, EC No. 238-883-1) is currently ongoing. A stepwise testing strategy is employed where the long-term toxicity to aquatic invertebrates study is being conducted first, with the results determining whether a long-term fish study will be proposed. The long-term Daphnia reproduction test will be read across to the registered substance. If there is a need for the long-term fish toxicity test with 3-(triethoxysilyl)propanethiol, this will also be read across to the registered substance.

The chemical safety assessment and PNECs will be revised once the long-term data are available.

3-(Trimethoxysilyl)propane-1-thiol and 3-(triethoxysilyl)propanethiol are structural analogues, the difference being that the registered substance contains methyl groups, whereas the analogue substance contains ethyl groups. Although this effects the rate of hydrolysis, both substances will hydrolyse and share a common silanol hydrolysis product, 3-(trihydroxysilyl)propanethiol. Both parent substances and silanol hydrolysis product contain a thiol side chain which is understood to drive the toxicity of the substance.

Justification for read-across is discussed in the RAAF report for ecotoxicity, attached in Section 13 of IUCLID and Annex 4 of the CSR.