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

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

No data on GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Concentration of sludge: 30 mg/L

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

TOC removal

Parameter:

other: BOD (NO2)

Value:

20

Sampling time:

28 d

Parameter:

other: BOD (NH3)

Value:

26

Sampling time:

28 d

Parameter:

% degradation (TOC removal)

Value:

28

Sampling time:

28 d

The test substance was hydrolyzed to form 2-Butanone oxime(2-0546, persistence, Low-Bioconcentration), Monomethylsilanol, and polymer (Polysiloxane) of the Monomethylsilanol. Analysis of the test substance was difficult.

Degradation % results were:

Indirect analysis	BOD (NO2)	BOD (NH3)
	28, 9, 24	36, 12, 31

 

Direct analysis	TOC
	34, 20, 31

 

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance butan-2-one O,O',O''-(methylsilylidyne)trioxime was determined to be not readily biodegradable under test conditions.

Executive summary:

The readily biodegradation test was performed by MITI according to OECD Guideline 301 C. 30 mg/L of activated sludge were exposed for 28 days to 100 mg/L of test item butan-2-one O,O',O''-(methylsilylidyne)trioxime. The biodegradation was analysed by indirect analysis, BOD (NO2) and BOD (NH3) obtaining a biodegradation of 20% and 26% respectively and by direct TOC analysis obtaining a biodegradation of 28%. The test substance was determined to be not readily biodegradable under test conditions.

The test substance was hydrolyzed to form 2-Butanone oxime (2-0546, persistence, Low-Bioconcentration), Monomethylsilanol, and polymer (Polysiloxane) of the Monomethylsilanol. Analysis of the test substance was difficult.

Description of key information

Key study: OECD Guideline 301 C. The test item butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined not to be readily biodegradable under the test conditions. The test substance was hydrolyzed to form 2-Butanone oxime(2-0546, persistence, Low-Bioconcentration), Monomethylsilanol, and polymer (Polysiloxane) of the Monomethylsilanol.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Key study: The readily biodegradation test was performed by MITI according to OECD Guideline 301 C. The test item

butan-2-one O,O',O''-(methylsilanetriyl)oxime was determined not to be readily biodegradable under the test conditions (degradation rates between 20 and 28 % after 28 days). The test substance was hydrolyzed to form 2-Butanone oxime(2-0546, persistence, Low-Bioconcentration), Monomethylsilanol, and polymer (Polysiloxane) of the Monomethylsilanol.

Supporting study: According the calculation method EPI-Suite, EPA (USA) / BIOWIN v4.10, butan-2-one O,O',O''-(methylsilanetriyl)oxime was predicted to not readily biodegradable.