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Environmental fate & pathways

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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 rapid hydrolysis of the parent substance, the distribution calculation is done for the silanol hydrolysis product.

Table: Distribution modelling for STP

Fraction of emission directed to air by STP



Fraction of emission directed to water by STP



Fraction of emission directed to sludge by STP



Fraction of the emission degraded in STP




3-Trimethoxysilylpropyl methacrylate hydrolyses rapidly to 3-(trihydroxysilyl)propyl methacrylate and methanol. 3-Trimethoxysilylpropyl methacrylate is readily biodegradable but failing the 10-day window. Once the biodegradation of the alkoxy groups is taken into account, there is evidence that the methacrylate side-chain is biodegrading to some extent, but as a worst case 3-(trihydroxysilyl)propyl methacrylate is considered to be not biodegradable. Methanol is readily biodegradable.

3-(Trihydroxysilyl)propyl methacrylate has very low Henry’s Law Constant, and low log Kow/log Koc. Distribution modelling for STP indicates that water is the main compartment to which 3-(trihydroxysilyl)propyl methacrylate is expected to partition in a sewage treatment plant. Water is also likely to be the main compartment to which it will partition in the wider environment.