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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Administrative data

Link to relevant study record(s)

Description of key information

the study does not need to be conducted, as the substance present low potential of bioaccumulation based on his high hydrolysis and low potential of bioaccumulation of its components.

The substance is found hydrolytically unstable with a half-life of 8.2 h at 50 C at pH 7. According to the EEC Directive 92/69, Section C.7, it can be concluded that the estimated half-life time is shorter than one day under representative environmental conditions (25ºC). Therefore, the registered substance was considered to be hydrolytically unstable.

According to R7b Guidance on information requirements, where the hydrolysis half-life, at environmentally relevant pH values (4-9) and temperature, is less than 12 hours, it may be appropriate to perform an exposure assessment, a hazard assessment and, if necessary, a bioaccumulation test on the relevant hydrolysis products instead of the parent substance. It should be noted that, in many cases, hydrolysis products are more hydrophilic and as a consequence will have a lower potential for bioaccumulation than the (registered) substance itself.

Y-15821 is a multicomponent reaction mixture with variable composition (UVCB). The variable composition results from the reaction of octanethioic acid, S-[3-(triethoxysilyl)propyl] ester (CAS# 220727-26-4) with 2-methyl-1,3-propane diol (CAS# 2163-42-  0), and 3-(triethoxysilyl)-1-propanethiol (CAS# 14814-09-6)  to yield a product by process, partially oligomeric product mixture.

Octanethioic acid, S-[3-(triethoxysilyl)propyl] ester (CAS# 220727-26-4) is as well hydrolytically unstable. Available study on the substance demonstrate its low potential to bioaccumulate in animal tissues as indicated by the very low BCF (BCF was calculated to be 20 at a test concentration of 2.5 mg/L) determined for fish. Hydrolysis products, were also taken in account in the study and their low bioaccumulation potential supported by a log Kow < 3.

3-(triethoxysilyl)-1-propanethiol (CAS# 14814-09-6) is as well hydrolytically unstable. No study is available, however Episuite QSAR calculations estimate a BCF of 59.11 (log BCF 1.772, logKow 2.93) indicating its low potential to bioaccumulate.

Key value for chemical safety assessment

Additional information