Butan-2-one O,O',O''-(vinylsilylidyne)trioxime

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
The test item undergoes rapid hydrolysis (half-life lower than 1h) in aqueous to 2-butanone oxime and vinylsilanetriol.
According to ECHA Guidance on Information Requirements and Chemical Safety Assessment. Chapter R.7b, section R.7.9.5.1 "Concluding on suitability for Classification and Labelling", data on primary biodegradability may be used for demonstrating rapid degradability only when it can be satisfactorily demonstrated that the degradation products formed do not fulfil the criteria for classification as hazardous to the aquatic environment.
Both identified degradation products do not fulfil the criteria for classification as hazardous to the aquatic environment according to available information (ECHA webpage).
According to section R.7.9.5.3 "Concluding on suitability for use in chemical safety assessment" of the above-mentioned ECHA Guidance, where the estimated degradation half-life is lower than 24 hours, this will provide clear evidence of environmental degradation, and consideration must be given to the identification and further evaluation of any degradation products.
The substance butan-2-one-O,O’,O’’-(vinylsilyldyne) trioxime has been demonstrated to undergo very fast hydrolysis (please see below cross-reference to hydrolysis summary).
Based on the above, data requirements for the present simulation study is waved based on hydrolysis and identification of degradation products.
For the degradation product 2-butanone oxime evidence of its ecotoxicological profile is provided in the dossier (please see below cross-reference to ecotoxicity studies and PBT assessment).
For the degradation product vinylsilanetriol, it is demonstrated that this substance undergoes condensation reactions to produce higher molecular weight siloxanes which are considered biologically unavailable (please see below attached justification).

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

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data waiving: supporting information

Transformation products:

yes

No.:

#1

No.:

#2

Reference 2

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with column 1 of REACH Annex IX, the sediment simulation test study does not need to be conducted as the substance and degradation products have no adsorption potential expected to sediment (Log Kow <3).

Reason / purpose for cross-reference:

data waiving: supporting information

Transformation products:

yes

No.:

#1

No.:

#2

Description of key information

Data waiving: The substance undergoes rapid hydrolysis (half-life < 1h) in aqueous to 2-butanone oxime and vinylsilanetriol. Thus, data requirements for the simulation test study on water is waved based on hydrolysis and identification of degradation products, and further evaluation of degradation products is considered.

Data waiving: In accordance with column 1 of REACH Annex IX,  the sediment simulation test study does not need to be conducted as the substance and degradation products have no adsorption potential expected to sediment.