Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Abiotic degradation

3-(Trimethoxysilyl)propiononitrile is predicted to hydrolyse rapidly (half-life 1.1 hours at pH 7 and 24.5°C). A half-life of 5.7 days for reaction with hydroxyl radicals in air has been calculated for 3-(trimethoxysilyl)propiononitrile. However, reaction with water vapour, rather than photolysis, may be the primary degradation process in air.

The initial hydrolysis products are expected to be 3-(trihydroxysilyl)propiononitrile and methanol.

Biotic degradation

A reliable ready biodegradation test has been read-across from an analogous substance which indicates that it is not readily biodegradable, and no significant biodegradation in water of the hydrolysis product, 3-(trihydroxysilyl)propiononitrile, 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.

Table 4.1.5 Degradation rates

Degradation rate in water:

Hydrolysis half-life: 1.1 hours at pH 7 and 20-25°C (predicted),for removal of parent. 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: 5.7 days for parent; 1.5 days for silanol hydrolysis product (predicted).