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Environmental fate & pathways

Biodegradation in water: screening tests

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Description of key information

Biodegradation in water, screening tests: Based on read-across from an analogous substance, no significant biodegradation of the silanol hydrolysis product, (3-chloropropyl)methylsilanediol, is expected.

Key value for chemical safety assessment

Additional information

There are no reliable ready biodegradation data available for (3-chloropropyl)dimethoxymethylsilane, therefore good quality data for the analogous substance, (3-chloropropyl)diethoxymethylsilane (CAS 13501-76-3), have been read across. Both substances share the same silanol hydrolysis product, (3-chloropropyl)methylsilanediol; the other hydrolysis products being methanol and ethanol, respectively, which are readily biodegradable.

Both (3-chloropropyl)dimethoxymethylsilane and (3-chloropropyl)diethoxymethylsilane are within an analogue group of substances within which, in general, there is no evidence of any significant biodegradation once biodegradation of alkoxy/acetoxy groups has been taken into account.

It is therefore considered valid to read-across the results for (3-chloropropyl)diethoxymethylsilane to fill the data gap for the registered substance. Additional information is given in a supporting report (PFA, 2013f) attached in Section 13 of the IUCLID 5 dossier.

56% biodegradation in 28 days was attained for


. This biodegradation is attributable to the biodegradation of the ethanol hydrolysis product. No significant biodegradation is expected for the silanol hydrolysis product. The study is considered to be reliability 1 (reliable without restrictions); the read across of the result is considered to be reliability 2 (reliable with restrictions).