Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint summary

Administrative data

Description of key information

Additional information


The test item totally hydrolysed after 1 hour at pH 1.2, 4, 7 and 9. Due to the fast hydrolysis even at 20°C the Tier 1 and Tier 2 of the OECD 111 guide is not applicable for the test item. The formation of hydrolysis products methanol and acetone oxime was demonstrated. Also a gel phase was formed at each pH value. After 1H-NMR analysis, it was confirmed that this precipitate contains vinyl moieties in various chemical environment.


The test results shows that the substance is not readily biodegradable (maximum of 23.6% after 28 days),but hydrolyses very fast :as showed in the hydrolysis study, hydrolyses fast withthe half-life time < 1 h at 25 °C andform oligomers and polymers.The log Kow values for two of three mayor components are higher than 4,5, but due to the rapid hydrolisisandformation of oligomers and polymers - molecules of very big molecular length (as well as molecular weight) of these molecules makes, that their uptake by a biological membrane is not likely and therefore the substance cannot be accumulate to a significant amount.


The substance undergoes rapid hydrolysis (half-life < 1h) in aqueous to acetone oxime, methanol and the corresponding silanols. At the same time, silanols undergo continuous condensation reaction to produce higher molecular weight siloxanes which are in the molecular weight range large enough to be considered biologically unavailable. Therefore, the potential for bioaccumulation of the test substance is likely due to the acetone oxime and methanol which has been calculated (EPISuite, BCFBAF v3.01). The BCF of the degradation products methanol and acetone oxime were calculated to be 3.162 L/kg.


The substance undergoes rapid hydrolysis (half-life < 1h) in aqueous to acetone oxime and the corresponding silanols. Also methanol was identified as a degradation product in the hydrolysis study included in this dossier. Therefore, the adsorption potential of the degradation products has been calculated (EPISuite, KOCWIN v2.00). Koc of methanol was estimated to be 1 L/kg and Log Koc = 0.0000. Koc of acetone oxime was estimated to be 60.7 L/kg and Log Koc = 1.7832.