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Ecotoxicological information

Short-term toxicity to aquatic invertebrates

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Description of key information

Short-term toxicity to invertebrates: 48 hour EC50 6.7 mg/l (nominal) (EU method C.2), read-across from an analogous substance, 3-trimethoxysilylpropane-1-thiol (CAS 4420-74-0). The EC50 is equivalent to 5.3 mg/l when expressed in terms of 3-(trihydroxysilyl)propanethiol.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
5.3 mg/L

Additional information

There are no reliable short-term invertebrate toxicity data available for 3-[dimethoxy(methyl)silyl]propanethiol (CAS 31001-77-1), therefore good quality data for an appropriate structural analogue, 3-trimethoxysilylpropane-1-thiol (CAS 4420-74-0), have been read across. Both substances have structurally similar silanol hydrolysis products, 3-(dihydroxymethylsilyl)propanethiol and 3- (trihydroxysilyl)propanethiol respectively. The other hydrolysis product is methanol in both cases.

A 48 hour E(L)C50 value of 6.7 mg/l and NOEC of 2.7 mg/l (nominal) have been determined for the effects of 3-trimethoxysilylpropane-1-thiol (CAS 4420-74-0) on mobility of Daphnia magna. In view of the test media preparation method and exposure regime it is likely that the test organisms were exposed primarily to the hydrolysis products of the tested substance. The EC50 is therefore equivalent to 5.3 mg/l when expressed in terms of 3-(trihydroxysilyl)propanethiol.

Refer to the discussion in the Section 6 endpoint summary for further discussion of the approach to chemical safety assessment for this registration substance, and justification for read-across used.