Registration Dossier

Diss Factsheets

Environmental fate & pathways

Endpoint summary

Administrative data

Description of key information

The substance, (3-chloropropyl)triethoxysilane (CAS 5089-70-3; EC No. 225-805-6), hydrolyses to (3-chloropropyl)silanetriol (CAS 64426-41-1) and ethanol (CAS 64-17-5; EC No. 200-578-6), with a hydrolysis half-life of greater than 12 hours but less than 48 hours (half-life 35 hours at pH 7 and 25°C). Therefore, the environmental hazard assessment for the aquatic compartment, including wastewater treatment plant, is based on the properties of the parent substance in accordance with REACH guidance for Chemical Safety Assessment (Chapter R16). The environmental hazard assessment for soil and sediment is considered for both the parent substance, (3-chloropropyl)triethoxysilane, and the silanol hydrolysis product, (3-chloropropyl)silanetriol; because the hydrolysis half-life is between 12 and 48 hours.


(3-Chloropropyl)silanetriol is the final product of hydrolysis reactions under conditions of a hydrolysis laboratory study and is the hydrolysis product relevant to conventional REACH Chemical Safety Assessment. However, other biotic or abiotic reactions may occur over longer time-scales in the environment.



ECHA (2016). REACH Guidance on Information Requirements and Chemical Safety Assessment Chapter R16: Environmental Exposure Assessment Version: 3.0. February 2016

Additional information