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Environmental fate & pathways

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Additional information

The distribution in a sewage treatment plant (STP) has been estimated using the SimpleTreat model (implemented in EUSES 2.1.2/Chesar 3), see table below. Due to the very rapid hydrolysis of dichloro(methyl)(phenyl)silane, the distribution calculation is done for the silanol hydrolysis product, methylphenylsilanediol.

Table: Distribution modelling for STP

Fraction of emission directed to water by STP

99.62

[%]

Fraction of emission directed to air by STP

6.82E-5

[%]

Fraction of emission directed to sludge by STP

0.374

[%]

Fraction of the emission degraded in STP

0

[%]

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 log Kow/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.