Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Abiotic degradation:

3-Chloropropyl(dimethoxy)methylsilane hydrolyses rapidly (0.1 h at pH 4, 1.3 h at pH 7 and 0.03 h at pH 9 and 20-25°C) under relevant environmental conditions to form 3-chloropropyl(methyl)silanediol and methanol. Reactions with water vapour rather than photolysis is likely to be the primary degradation process in air.

Biotic degradation:

A biodegradation in water study has been read across from a relevant analogous substance. The result indicates that no significant biodegradation in water of the hydrolysis product, 3-chloropropyl(methyl)silanediol, is expected. The chemical safety assessment indicates that it is not necessary to obtain further information on biodegradation via simulation tests in water, sediment or soil.

Additional information

Table: Degradation rates

Degradation rate in water:

Hydrolysis half-life: 1.3 hours at pH 7 and 20-25°C, for removal of parent (predicted). No significant biodegradation of silanol hydrolysis product expected.

Degradation rate in sediment:

No significant biodegradation of silanol hydrolysis product expected.

Degradation rate in soil:

No significant biodegradation of silanol hydrolysis product expected.

Degradation rate in air:

Half-life for reaction with hydroxyl radicals in air: 4.1 days for parent; 1.8 days for silanol hydrolysis product (predicted).