Registration Dossier

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

Additional information

Abiotic degradation

3-Trimethoxysilylpropyl methacrylate hydrolyses rapidly (half-lives at 20°C of 1.87 h at pH 7, 0.018 at pH 4 and 0.068 at pH 9; see Section 4.1.1.1). A half-life of 0.6 days for reaction with hydroxyl radicals in air has been calculated for 3-trimethoxysilylpropyl methacrylate.

The hydrolysis products are 3-(trihydroxysilyl)propyl methacrylate and methanol. A half-life of 0.5 days for reaction with hydroxyl radicals in air has been calculated for 3-(trihydroxysilyl)propyl methacrylate.

Biotic degradation

Based on biodegradation in water studies, it is concluded that the substance is readily biodegradable but failing the 10-day window. No significant biodegradation of the silanol hydrolysis product, 3-(trihydroxysilyl)propyl methacrylate 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. Degradation rates - summary

Degradationrate in water:

Hydrolysis half-life: 1.87 hours at pH 7 and 20°C for removal of parent (measured). 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. No significant biodegradation expected for the silanol hydrolysis product.

Degradation rate in sediment:

Hydrolysis may occur (hydrolysis half-life in water 1.87 h at 20°C (measured)). No significant biodegradation expected for the silanol hydrolysis product.

Degradation rate in soil:

Hydrolysis may occur (hydrolysis half-life in water 1.87 h at 20°C (measured)). No significant biodegradation expected for the silanol hydrolysis product.

Degradation rate in air:

Half-life for reaction with hydroxyl radicals in air of the parent substance: 0.6 days (calculated)

Half-life for reaction with hydroxyl radicals in air of silanol hydrolysis product: 0.5 days (calculated).