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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). As the parent substance hydrolyses very rapidly, the distribution calculation is done for the hydrolysis products, tris(1-methylethyl)silanol and acrylic acid. In practice there is no direct release of the substance or its hydrolysis product to waste water.

Table: Distribution modelling for STP

tris(1-methylethyl)silanol

Acrylic acid

 

Fraction of emission directed to water by STP

95.91

12.65

 [%]

 Fraction of emission directed to air by STP

2.492

5.58E-3

 [%]

 Fraction of emission directed to sludge by STP

1.591

6.3E-3

 [%]

 Fraction of the emission degraded in STP

 0

 87.33

 [%]

Tri(isopropyl)silyl acrylate hydrolyses rapidly to tris(1-methylethyl)silanol and acrylic acid. Tris(1-methylethyl)silanol is not expected to undergo any significant biodegradation, and is predicted to have low Henry’s Law constant. 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 tris(1-methylethyl)silanol will partition in the wider environment. For acrylic acid, water is also expected to be the main compartment to which it is expected to partition.