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

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The analogue VAC3 component of the reaction mass Wasox-VMAC2, has a molecular structure similar to butan-2-one O,O',O''-(methylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for abiotic degradation.
See attached reporting format.

Reason / purpose for cross-reference:

read-across source

Preliminary study:

Based on read-across approach from analogue substance VAC3 (component of reaction mass Wasox-VMAC2), the preliminary test indicated that the half-life was shorter than 1 hour at 25 °C and at pH 4, pH 7 and pH 9. Therefore, it was considered to be easily hydrolysable and no main test was performed, according to the guideline.

Test performance:

Based on read-across approach from analogue substance VAC3 (component of reaction mass Wasox-VMAC2), the concentration was determined at the earliest possible time, i.e. 0.75 h after the start of the dissolution. Later sampling times was not required as the concentrations was already below the limit of quantification at 0.75 h.

Transformation products:

no

Key result

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

> 1 h-1

DT50:

< 1 h

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: (results based on analogue substance acetone O,O',O''-(vinylsilanetriyl)oxime)

Other kinetic parameters:

Based on read-across approach from analogue substance, no kinetic of the hydrolysis could be determined because of the slow dissolution of the test substance and the fast hydrolysis.

Details on results:

Based on read-across from experimental results with analogue substance VAC3 (component of reaction mass Wasox-VMAC2), the test item butan-2-one O,O',O''-(methylsilanetriyl)oxime is determined to hydrolyse in less than 1 hour at 25 ºC.

Validity criteria fulfilled:

not applicable

Conclusions:

Based on the read-across approach from experimental results obtained with analogue VAC3, butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Executive summary:

Based on the experimental results obtained with analogue substance VAC3 (half-life <1 hour at pH 4, 7 and 9 at 25 ºC), the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Reference 2

Endpoint:

hydrolysis

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The analogue MAC3 component of the reaction mass Wasox-MMAC2, has a molecular structure similar to butan-2-one O,O',O''-(methylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for abiotic degradation.
See attached reporting format.

Reason / purpose for cross-reference:

read-across source

Preliminary study:

Based on read-across approach from analogue substance MAC3 (component of reaction mass Wasox-MMAC2), the preliminary test indicated that the half-life was shorter than 1 hour at 25 °C and at pH 4, pH 7 and pH 9. Therefore, it was considered to be easily hydrolysable and no main test was performed, according to the guideline.

Test performance:

Based on read-across approach from analogue substance MAC3 (component of reaction mass Wasox-MMAC2), the concentration was determined at the earliest possible time, i.e. 0.75 h after the start of the dissolution. Later sampling times was not required as the concentrations was already below the limit of quantification at 0.75 h.

Transformation products:

no

Key result

pH:

4

Temp.:

25 °C

Hydrolysis rate constant:

> 1 h-1

DT50:

< 1 h

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: (results based on analogue substance Propan-2-one-O,O',O''-(methylsilantriyl)trioxime)

Other kinetic parameters:

Based on read-across approach from analogue substance, no kinetic of the hydrolysis could be determined because of the slow dissolution of the test substance and the fast hydrolysis.

Details on results:

Based on read-across from experimental results with analogue substance MAC3 (component of reaction mass Wasox-MMAC2), the test item butan-2-one O,O',O''-(methylsilanetriyl)oxime is determined to hydrolyse in less than 1 hour at 25 ºC.

Validity criteria fulfilled:

not applicable

Conclusions:

Based on the read-across approach from experimental results obtained with analogue MAC3, butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Executive summary:

Based on the experimental results obtained with analogue substance MAC3 (half-life <1 hour at pH 4, 7 and 9 at 25 ºC), the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Reference 3

Endpoint:

hydrolysis

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
The analogue Propyltriacetoxysilane has a molecular structure similar to butan-2-one O,O',O''-(methylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for abiotic degradation.
See attached reporting format.

Reason / purpose for cross-reference:

read-across source

Preliminary study:

The preliminary test on analogue propyltriacetoxysilane was not performed due to the known instability of the test item.

Transformation products:

yes

No.:

#1

No.:

#2

Details on hydrolysis and appearance of transformation product(s):

Based on the experimental results with analogue propyltriacetoxysilane and applying the read-across approach, it was determined that butan-2-one O,O',O''-(methylsilanetriyl)oxime hidrolyses into free butanone oxime as the main hydrolysis product and silanols with fast kinetics of polycondensation reactions.

Key result

pH:

1.2

Temp.:

22 °C

DT50:

< 0.625 min

Remarks on result:

other: (results obtained with analogue substance propyltriacetoxysilane)

Key result

pH:

4

Temp.:

22 °C

DT50:

< 0.625 min

Remarks on result:

other: (results obtained with analogue substance propyltriacetoxysilane)

Key result

pH:

7

Temp.:

22 °C

DT50:

< 0.625 min

Remarks on result:

other: (results obtained with analogue substance propyltriacetoxysilane)

Key result

pH:

9

Temp.:

22 °C

DT50:

< 0.625 min

Remarks on result:

other: (results obtained with analogue substance propyltriacetoxysilane)

Other kinetic parameters:

Due to the extremely fast hydrolysis reaction of analogue propyltriacetoxysilane, a detailed determination of rate constants and half-life times was technically not possible.

Details on results:

Based on experimental results obtained with analogue propyltriacetoxysilane where hydrolysis was finished at least 150 seconds after the initial contact of the test item with water and the maximum half life time of test item was determined to be 37.5 seconds at pH 1.2, 4, 7 and 9, the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically unstable, with a fast hydrolysis and low half-life regardless of pH.

Validity criteria fulfilled:

not applicable

Conclusions:

Based on the read-across approach from experimental results on analogue propyltriacetoxysilane, butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically unstable, with a fast hydrolysis (very low half-life time) into butanone oxime and silanols regardless of pH.

Executive summary:

The abiotic degradation of analogue substance propyltriacetoxysilane was performed according to OECD Guideline 111. The stepwise hydrolysis with formation of acetic acid as the main hydrolysis product and the presence as well as the fast kinetics of polycondensation reactions of the forming silanols (trihydroxypropylsilane) could be observed. The hydrolysis of analogue propyltriacetoxysilane was completed at least 150 seconds at pH 1.2, 4, 7 and 9 after the initial contact of the test item with water. A minimum of four completed half life cycles were estimated for the test item in a reaction time of 150 seconds and therefore the maximum half life time of <37.5 seconds was estimated for propyltriacetoxysilane. Based on these results, the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be rapidly hydrolysed into butanone oxime and corresponding silanols in contact with water regardless of pH.

Description of key information

Weight of evidence: Read-across approach from analogue VAC3 (OECD 111 and GLP): Butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a very low half-life.

Weight of evidence: Read-across approach from analogue MAC3 (OECD 111 and GLP): Butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a very low half-life.

Weight of evidence: Read-across approach from analogue propyltriacetoxysilane (OECD 111 and GLP): Butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically unstable, with a fast hydrolysis (very low half-life time) into butanone oxime and silanols regardless of pH.

Additional information

Read-across approach from experimental results on analogue substance VAC3:

Weight of evidence: Based on the experimental results obtained with analogue substance VAC3 in a study performed according to OECD 111 and GLP (half-life <1 hour at pH 4, 7 and 9 at 25 ºC), the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Read-across approach from experimental results on analogue substance MAC3:

Weight of evidence: Based on the experimental results obtained with analogue substance MAC3 in a study performed according to OECD 111 and GLP (half-life <1 hour at pH 4, 7 and 9 at 25 ºC), the read-across approach was applied and butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically instable with a low half-life.

Read-across approach from experimental results on analogue substance propyltriacetoxysilane:

Weight of evidence: Based on the read-across approach from experimental results obtained in a study performed in accordance with OECD 111 and GLP on analogue propyltriacetoxysilane (half-life <37.5 seconds at 25 ºC regardless pH), butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined to be hydrolytically unstable, with a fast hydrolysis (very low half-life time) into butanone oxime and silanols.