Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Dichloro(methyl)(phenyl)silane hydrolyses very rapidly to methylphenylsilanediol and hydrochloric acid. Biodegradation is not relevant for hydrochloric acid being inorganic. Methylphenylsilanediol is not expected to undergo any significant biodegradation, and is predicted to have low Henry’s Law constant and low logKow/log Koc. Distribution modelling for STP indicates that water is the main compartment to which it is expected to partition in a sewage treatment plant. Water is also likely to be the main compartment to which methylphenylsilanediol will partition in the wider environment.

Additional information

Table: Degradation rates

Degradation rate in water:

Hydrolysis half-life: <1 minute at pH 7 and 1.5°C, 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: 7.6 days for parent; 1.8 days for silanol hydrolysis product (predicted).