Registration Dossier

Diss Factsheets

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).