Registration Dossier

Ecotoxicological information

Toxicity to microorganisms

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
activated sludge respiration inhibition testing
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''-(vinylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for toxicity to microorganisms.
Reason / purpose:
read-across source
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 420.04 mg/L
Nominal / measured:
estimated
Conc. based on:
other: (analogue substance)
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Remarks on result:
other: (Based on read-across approach on an analogue)
Details on results:
Based on the experimental results on analogue substance Wasox-MMAC2 (EC50-3h > 300 mg/L for activated sludge of a predominantly domestic sewage), the read-across approach was applied and the EC50 (3h) for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 420.04 mg/L.
Validity criteria fulfilled:
not applicable
Conclusions:
Based on read-across approach from experimental data on analogue Wasox-MMAC2, the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 420.04 mg/L.
Executive summary:

An Activated Sludge, Respiration Inhibition Test was performed on analogue Wasox-MMAC2 according to the OECD Guideline 209 using activated sludge from a sewage treatment plant treating predominantly domestic sewage. The 3h-EC50 was determined to be > 300 mg/L, basis for effect: respiration rate. Based on these results, the read-across approach was applied and the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 420.04 mg/L.

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
October 5, 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
According to OECD Guideline 209, with GLP.
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 850.6800 (Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals)
GLP compliance:
yes
Analytical monitoring:
no
Details on sampling:
- Concentrations: 7.6, 19.2, 48.0, 120.0 and 300.0 mg of the test substance/L
- Sampling method: The appropriate amounts of the test substance were added to the sludge samples at the beginning of the incubation
- Sample storage conditions before analysis: to assure that the non altered test substance was tested as far as possible, no stock solution was prepared.
Vehicle:
no
Details on test solutions:
The test substance was poorly soluble in water and hydrolyses and polymerises quickly when in contact with water. To assure that the non altered test substance was tested as far as possible, no stock solution/suspension was prepared but the appropriate amounts of the test substance were added to the sludge samples at the beginning of the incubation. This treatment is in accordance with the EPA-Guideline OPPTS 850.6800.
Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
- Preparation of inoculum for exposure: A sample of activated sludge was collected one day before the test. The container for transportation was only about 2/3 filled in order to maintain the contact with air. At arrival in the laboratory (less than 1 hour after sample collection), the supernatant over the sludge was decanted, the sludge was diluted with tap water and aerated by means of compressed air. 50 mL of synthetic sewage concentrate were added per litre each day. On the day of the test the sludge was allowed to sediment and the supernatant was decanted.
On the basis of this calculation the concentration of suspended solids was adjusted to 4 g/L with tap water
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Test temperature:
The temperature in the samples was 18 ºC
pH:
The pH of the incubation mixtures after the 3 hour incubation was between 8.29 and 8.37, the pH of the negative control samples was 8.39 and 8.34. The test substance did not influence the pH.
Dissolved oxygen:
Negative controls: 6.98-7.56 mg/mL
Test substance: 6.37-7.51 mg/mL
Positive controls: 6.79 -8.74 mg/L
Nominal and measured concentrations:
nominal concentrations: 7.7, 19.2, 48, 120, and 300 mg/mL
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: Glass beakers with a nominal volume of 1000 mL
- Aeration: the samples were aerated at flow rate of 0.7 L/min
- Type of flow-through (e.g. peristaltic or proportional diluter): oil free compressed air and a Pasteur-pipette as aeration device
- Renewal rate of test solution (frequency/flow rate): Samples were aerated for 3 hours.


EFFECT PARAMETERS MEASURED (with observation intervals if applicable): the amount of dry substance in the standardized activated sludge. The pH of the standardized sludge, and the temperature in the samples.

Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol
Duration:
3 h
Dose descriptor:
other: EC20
Effect conc.:
189 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 300 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC80
Effect conc.:
> 300 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: The EC50 of 3,5-dichlorophenol was in the accepted range of 5 to 30 mg/L. The actual values of the EC20, EC50 and EC80 for 3,5-dichlorophenol were: EC20 = 6.2 mg/L, EC50 = 12.8 mg/L, EC80 = 26.4 mg/L

Reported statistics and error estimates:
For each sample a linear regression was calculated from the linear part of the graph time versus oxygen content. From the oxygen content at the begin and at the end of this regression line the respiration rates (expressed in mg O2.L-1.h-1) were calculated.
The concentrations of the test substance around 50 % inhibition (if such data exist) and the concentrations of the positive control are converted to log10. These values and the corresponding percentage of inhibition are subjected to linear regression analysis. These analyses are used to obtain the regression coefficients and the respective EC20, EC50 and EC80 values.

Respiration rate and inhibition of the samples

Negative values indicate enhanced respiration compared to the control cultures.


sample

final
concentr. (mg/L)

linear range (minutes)


mg O2/ L
at begin


mg O2/ L
at end


respiration rate
(mg O2. L-1. h-1)

percent
respiration
inhibitio

neg. control 1

0.0

8.04

6.98

2.63

32.46

3.42

test substance 1

7.6

9.48

7.09

2.15

31.27

6.98

test substance 2

19.2

7.00

7.03

3.25

32.40

3.61

test substance 3

48.0

7.44

6.37

2.35

32.42

3.55

test substance 4

120.0

8.00

6.94

3.11

28.73

14.54

test substance 5

300.0

7.96

7.51

4.19

25.03

 25.55

neg. control 2

0.0

7.56

7.06

2.68

34.76

-3.42

DCP 1

4.9

7.96

6.79

2.62

31.43

6.49

DCP 2

11.9

9.52

7.69

5.26

15.32

 54.44

DCP 3

29.2

6.60

8.74

8.02

6.55

 80.53

DCP: 3,5-dichlorophenol

Validity criteria fulfilled:
yes
Conclusions:
EC20: 189 mg/L; EC50: > 300 mg/L and EC80: > 300 mg/L
Executive summary:

The study was performed to estimate possible effects of Wasox-VMAC2 on aerobic microbial sewage treatment plants. The test was performed according to the OECD Guideline 209 and the EU Method C11, using activated sludge from a sewage treatment plant treating predominantly domestic sewage. Five concentrations of the test substance (7.6, 19.2, 48.0, 120.0 and 300.0 mg/L) were tested versus two negative controls (tap water). As positive control substance 3,5-dichlorophenol was used and tested in three concentrations (4.9, 11.9 and 29.2 mg/L). The test results fulfilled the criteria for validity. The following EC values were obtained EC20: 189 mg/L; EC50: > 300 mg/L and EC80: > 300 mg/L.

Endpoint:
activated sludge respiration inhibition testing
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
October 5, 2004
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
According to OECD Guideline 209, with GLP.
Qualifier:
according to
Guideline:
OECD Guideline 209 (Activated Sludge, Respiration Inhibition Test
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.11 (Biodegradation: Activated Sludge Respiration Inhibition Test)
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 850.6800 (Modified Activated Sludge, Respiration Inhibition Test for Sparingly Soluble Chemicals)
GLP compliance:
yes
Analytical monitoring:
no
Details on sampling:
- Concentrations: 7.6, 19.2, 48.0, 120.0 and 300.0 mg of the test substance/L
- Sampling method: The appropriate amounts of the test substance were added to the sludge samples at the beginning of the incubation
- Sample storage conditions before analysis: to assure that the non altered test substance was tested as far as possible, no stock solution was prepared.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was poorly soluble in water and hydrolyses and polymerises quickly when in contact with water. To assure that the non altered test substance was tested as far as possible, no stock solution/suspension was prepared but the appropriate amounts of the test substance were added to the sludge samples at the beginning of the incubation. This treatment is in accordance with the EPA-Guideline OPPTS 850.6800.
- Controls: Positive control: A stock solution of 3,5-dichloraphenol (nominally 0.5 g/L) was prepared by dissolving 50 mg of the substance in 100 mL of deionised water. Three concentrations, nominally from 5 to 30 mg/L. No NaOH was used to increase the solubility of dichloraphenol, therefore no adjustment of the pH was necessary.
- Controls: Negative control
Test organisms (species):
activated sludge of a predominantly domestic sewage
Details on inoculum:
- Preparation of inoculum for exposure: A sample of activated sludge was collected one day before the test. The container for transportation was only about 2/3 filled in order to maintain the contact with air. At arrival in the laboratory (less than 1 hour after sample collection), the supernatant over the sludge was decanted, the sludge was diluted with tap water and aerated by means of compressed air. 50 mL of synthetic sewage concentrate were added per litre each day. On the day of the test the sludge was allowed to sediment and the supernatant was decanted.
- Initial biomass concentration: Concentration of suspended solids was adjusted to 4 g/L with tap water
- Other: The inoculum was aerated until use.
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
3 h
Test temperature:
18 ºC
pH:
8.31-8.42
Nominal and measured concentrations:
Nominal concentrations test item: 0 (control), 7.7, 19.2, 48, 120, and 300 mg/mL
Nominal concentration positive control (3,5-dichlorophenol): 5, 12.2 and 30 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Glass beakers
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: Glass beakers, nominal volume of 1000 mL
- Aeration: flow rate of 0.7 L/min using oil free compressed air and Pasteur-pipette as aeration device.
- No. of organisms per vessel: 4 g/L
- No. of vessels per concentration (replicates): 1 (5 concentration)
- No. of vessels per positive control (replicates): 3
- No. of vessels per negative control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
All incubation mixtures were prepared by mixing 200 mL of microbial inoculum and 200 mL of synthetic sewage solution with 100 mL of tap water and/or the appropriate amount of the test or control substance in glass beakers with a nominal volume of 1000 mL.

OTHER TEST CONDITIONS
- Adjustment of pH: Yes
- Photoperiod:
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): The oxygen concentration was determined with a DO meter "OXI Level 2" and an oxygen electrode. Respiration rates (in mg O2.L-1.h-1) were determined in aliquots of the incubation mixtures. Bottles with narrow neck and a volume of about 100 mL were filled with the sample and positioned on a magnetic stirrer. Then the oxygen electrode (equipped with a magnetic stirring wheel) was inserted in a way that no air remained in the bottle and that the electrode sealed the bottle neck to avoid contact of the sample with the atmosphere. The decline of oxygen concentration was measured by recording the concentrations of oxygen at various times. pH was determined with a pH-meter in the standardised microbial inoculum before the test and in each sample at the end of the incubation and aeration. The test was performed in a temperature controlled room with automatic temperature registration. The temperature inside the samples was measured with a mercury thermometer.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: The highest concentration of the test substance corresponds to the scheme given in the guidelines. The spacing between the concentrations of 2.5 is within the permitted range of 'not more than 3.2'. The amount of concentrations tested is in agreement with the guidelines which require 'at least 5'. The concentrations of 3,5-dichlorophenol were set around the expected EC50 of 5 to 30 mg/L.
- Test concentrations: Test item: 0 (control), 7.7, 19.2, 48, 120 and 300 mg/L. Positive control: 5, 12.2 and 30 mg/L.
Reference substance (positive control):
yes
Remarks:
3,5-dichlorophenol
Duration:
3 h
Dose descriptor:
other: EC20
Effect conc.:
80 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Remarks on result:
other: (95% CL: 35-125 mg/L)
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 300 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Duration:
3 h
Dose descriptor:
other: EC80
Effect conc.:
> 300 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Details on results:
The test substance inhibited the respiration of the activated sludge only at higher concentrations and only slightly. The highest obtained inhibition was 27.2 % at 300 mg/L.
Usually occurring foam formation during incubation was suppressed by the test substance.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: The ECso of 3,5-diehlorophenol was in the accepted range of 5 to 30 mg/L. The actual values of the EC20, EC50 and EC80 for 3,5-diehlorophenol were: EC20= 6.2 mg/L; EC50= 12.8 mg/L; EC80= 26.3 mg/L

Reported statistics and error estimates:
For each sample a linear regression was calculated from the linear part of the graph time versus oxygen content. From the oxygen content at the begin and at the end of this regression line the respiration rates (expressed in mg O2.L-1.h-1) were calculated.
The concentrations of the test substance around 50 % inhibition (if such data exist) and the concentrations of the positive control are converted to log10. These values and the corresponding percentage of inhibition are subjected to linear regression analysis. These analyses are used to obtain the regression coefficients and the respective EC20, EC50 and EC80 values.

Respiration rate and inhibition of the samples

Negative values indicate enhanced respiration compared to the control cultures.


sample

final
concentr. (mg/L)

linear range (minutes)

mg O2/ L
at begin

mg O2/ L
at end

respiration rate
(mg O2. L-1. h-1)

per cent
respiration
inhibition

neg. control 1

0.0

8.00

7.00

2.67

32.48

3.53

test substance 1

7.6

9.48

7.23

2.59

29.37

12.76

test substance 2

19.2

8.48

7.11

2.72

31.06

7.73

test substance 3

48.0

8.44

6.64

2.80

27.30

18.91

test substance 4

120.0

8.60

7.18

3.54

25.40

24.56

test substance 5

300.0

8.52

7.32

3.84

24.51

27.20

neg. control 2

0.0

8.04

7.06

2.39

34.85

-3.53

DCP 1

4.9

8.40

6.80

2.38

31.57

6.21

DCP 2

11.9

9.52

7.68

5.25

15.32

54.50

DCP 3

29.2

7.08

8.02

8.02

6.53

80.62

DCP: 3,5-dichlorophenol

Validity criteria fulfilled:
yes
Remarks:
(The respiration rates of the two negative control samples were within 15 % of each other; the EC50 of 3,5-diehlorophenol was in the accepted range of 5 to 30 mg/L)
Conclusions:
EC50 value (based on respiration inhibition) on activated sludge at 3 hours exposure period was > 300 mg/l.
Executive summary:

The study was performed to estimate possible effects of WASOX-MMAC2 on aerobic microbial sewage treatment plants. The test was performed according to the OECD Guideline 209, using activated sludge from a sewage treatment plant treating predominantly domestic sewage. Five concentrations of the test substance (7.6, 19.2, 48.0, 120.0 and 300.0 mg/L) were tested versus two negative controls (tap water). As positive control substance 3,5-dichlorophenol was used and tested in three concentrations (4.9, 11.9 and 29.2 mg/L). The microbial inoculum was a preparation of activated sludge collected one day before the test. The concentration of the microbial inoculum was adjusted to 4 g of dry weight per litre which gives a final amount of 1.6 g dry weight per litre. The respiration rates of the two negative control samples were within 15 % of each other (± 3.5 ) and the EC50 of 3,5-dichloraphenol was in the accepted range of 5 to 30 mg/L (12.8 mg/L) . The test substance inhibited the respiration of the activated sludge only at higher concentrations and only slightly. The highest obtained inhibition was 27.2 %. The obtained EC-3h for Wasox-MMAC2 were: EC20: 80 mg/L; EC50: > 300 mg/L and EC80: > 300 mg/L.

Endpoint:
activated sludge respiration inhibition testing
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''-(vinylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for toxicity to microorganisms.
Reason / purpose:
read-across source
Key result
Duration:
3 h
Dose descriptor:
EC50
Effect conc.:
> 406.02 mg/L
Nominal / measured:
estimated
Conc. based on:
other: (analogue substance)
Basis for effect:
inhibition of total respiration
Remarks:
respiration rate
Remarks on result:
other: (Based on read-across approach from an analogue)
Details on results:
Based on the experimental results on analogue substance Wasox-VMAC2 (EC50-3h > 300 mg/L) for activated sludge of a predominantly domestic sewage), the read-across approach was applied and the EC50 (3h) for EAC3 was calculated to be > 406.02 mg/L.
Validity criteria fulfilled:
not applicable
Conclusions:
Based on read-across approach from experimental data on analogue Wasox-VMAC2, the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 406.02 mg/L.
Executive summary:

An Activated Sludge, Respiration Inhibition Test was performed on analogue Wasox-VMAC2 according to the OECD Guideline 209 using activated sludge from a sewage treatment plant treating predominantly domestic sewage. The 3h-EC50 was determined to be > 300 mg/L, basis for effect: respiration rate. Based on these results, the read-across approach was applied and the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 406.02 mg/L.

Endpoint:
toxicity to microorganisms, other
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
From January 13 to February 10, 2012
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Remarks:
According to OECD 301 F. GLP study
Qualifier:
according to
Guideline:
other: OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
GLP compliance:
yes (incl. certificate)
Vehicle:
no
Test organisms (species):
activated sludge
Details on inoculum:
- Initial biomass concentration: 30 mg/L
- Source of inoculum/activated sludge: Aeration tank of Sewage Treatment Plant "Czajka" Warsaw.
- Storage conditions: The coarse particles were removed by filtration. Such prepared sludge was washed in the medium and was placed in laboratory-scale unit where the aerobic conditions were maintained by means of an intense aeration with compressor and aerators.
- Preparation of inoculum for exposure: The concentrated sludge was suspended in mineral medium to yield a concentration of 3-5 g suspended solids/l and it was aerated until application. After complete re-suspension was achieved, a sample was withdrawn just before use for the determination of the dry weight of the suspended solids.
- Pretreatment: Inocula was pre-conditioned to the experimental conditions. Pre-conditioning consisted of aerating activated sludge in mineral medium for 5 days at the test temperature of 22 ºC.
- Initial biomass concentration: 30 mg/L SS
Test type:
other: Readily biodegradability
Water media type:
freshwater
Limit test:
no
Total exposure duration:
28 d
Test temperature:
22 ± 2 ºC.
pH:
6-8.5
Nominal and measured concentrations:
100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: Closed WTW OxiTop OC 110 respirometer for BOD determination
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 164 ml volume
- Aeration: aerobic conditions
- No. of organisms per vessel: 30 mg/L SS activated sludge inoculum
- No. of vessels per concentration (replicates):
Test solution: 3 replicates, each containing 100 mg/L test item and 30 mg/L SS inoculum.
Inoculum blank: 3 replicates, each containing 30 mg/L SS inoculum.
Procedure control: 3 replicates, each containing 100 mg/L reference item (sodium acetate) and 30 mg/L SS inoculum.
Toxicity control: 3 replicates, each containing 100 mg/L test item, 100 mg/L reference item (sodium acetate) and 30 mg/L SS inoculum.

TEST MEDIUM / WATER PARAMETERS
- Preparation of test solutions:
The solutions of the test and reference items were prepared, in separate batches, in mineral medium equivalent to a concentration of 100 mg chemical/litre, using stock solutions. The pH values were adjusted to 7,4 ± 0,2. with 0.1N NaOH. The requisite volume of solutions of test and reference items, were introduced respectively, into triplicate flasks. 16.4 ml of stock solutions of test and reference items were introduced into the right flasks. Mineral medium only was added to further flasks (for inoculum controls). Potassium hydroxide solution (0.66 ml of 45% KOH) was added to each of the CO2-absorber compartments. The determined content of inoculum at the end of preconditioning was equal to 5.31 mg suspended solids/l. To give a concentration of suspended solids equal to 30 mg/l in each flask, 0.93 ml of preconditioned suspension of inoculum was added into each flask. The flasks were made up to 164 ml volume with prepared mineral medium.

OTHER TEST CONDITIONS
- Adjustment of pH: yes, pH was adjusted to 7.54 with 0.1N NaOH.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Biodegradation % based on oxygen consumption.

TEST CONCENTRATIONS
- Test concentrations: 100 mg/L
Key result
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: % biodegradation
Details on results:
The NOEC of methyltriacetoxysilane was determined to be 100 mg/L since the substance degrades well (79.5% of biodegradation at 28 days) and did not inhibit the degradation in the toxicity test (83.9% of biodegradation after 28 days) up to 100 mg/L.

Table: Sample oxygen uptake: biodegradability

 

time, days

3

5

7

9

12

14

16

18

21

23

25

28

Test item O2uptake, mg/dm3

a1

72.4

89.6

101.5

107.5

114.0

117.2

118.0

119.0

121.5

124.7

127.2

129.6

a2

68.1

83.3

92.3

98.9

106.1

111.3

113.6

114.8

117.0

119.2

121.5

123.7

a3

65.6

81.6

91.7

98.5

107.0

110.1

112.9

114.0

115.3

118.8

121.6

123.5

am. avg

68.7

84.8

95.1

101.6

109.0

112.9

114.8

115.9

117.9

120.9

123.4

125.6

Blank test O2uptake. mg/dm3

b1

8.7

13.8

17.5

20.2

28.6

32.1

37.0

39.8

42.5

42.2

44.7

45.8

b2

5.0

9.3

11.4

14.5

21.6

30.9

31.2

33.3

34.9

35.2

37.2

38.8

b3

8.4

12.2

13.4

16.9

27.7

34.2

36.2

39.7

42.8

42.5

43.2

45.5

bm. avg

7.4

11.8

14.1

17.2

26.0

32.4

34.8

37.6

40.0

40.0

41.7

43.4

Referencet item O2uptake. mg/dm3

w1

53.1

67.0

74.7

79.8

87.6

90.5

93.3

96.3

100.9

101.0

104.0

106.7

w2

59.7

71.0

79.6

85.5

91.8

95.2

97.1

98.5

101.0

101.0

103.7

104.0

w3

59.8

75.6

83.0

89.4

95.9

98.3

100.8

101.0

104.0

105.6

107.0

110.5

wm. avg

57.5

71.2

79.1

84.9

91.8

94.6

97.1

98.6

102.0

102.5

104.9

107.0

Toxicity control O2uptake. mg/dm3

tox1

110.6

132.1

143.5

152.0

162.2

167.6

170.8

175.9

180.6

186.4

189.8

195.4

tox2

131.8

155.0

166.0

172.6

179.0

182.4

185.7

189.3

191.8

195.3

198.0

202.7

tox3

116.8

139.1

154.4

163.7

172.0

174.0

177.0

180.6

183.0

185.0

186.0

188.7

toxm. avg

119.7

142.1

154.7

162.8

171.1

174.7

177.9

181.9

185.2

188.9

191.3

195.6

 

Corrected

BOD. mg/dm3

(a1-bm)

65.0

77.8

87.4

90.3

88.1

84.8

83.2

81.4

81.4

84.8

85.5

86.2

(a2-bm)

60.7

71.6

78.2

81.7

80.1

78.9

78.8

77.2

76.9

79.3

79.8

80.3

(a3-bm)

58.3

69.8

77.6

81.3

81.0

77.7

78.1

76.4

75.3

78.8

79.9

80.1

test item

% degradation

ThOD = 103.4

mgO2/l

R1(a1)

62.9

75.3

84.5

87.3

85.2

82.1

80.4

78.7

78.7

82.0

82.7

83.4

R2(a2)

58.7

69.2

75.6

79.1

77.5

76.3

76.3

74.6

74.4

76.7

77.2

77.7

R3(a3)

56.3

67.5

75.1

78.6

78.4

75.2

75.5

73.9

72.8

76.2

77.3

77.5

R. avg

59.3

70.7

78.4

81.7

80.3

77.8

77.4

75.7

75.3

78.3

79.0

79.5

reference item

% degradation

ThOD = 78.0

mgO2/l

R1(tox1)

58.6

70.8

77.7

80.3

79.0

74.5

75.0

75.3

78.0

78.3

79.9

81.1

R2(tox2)

67.1

75.9

84.0

87.6

84.5

80.5

79.9

78.1

78.1

78.3

79.5

77.7

R3(tox3)

67.2

81.8

88.4

92.5

89.7

84.5

84.6

81.3

82.0

84.2

83.8

86.0

Rtoxavg

64.3

76.2

83.3

86.8

84.4

79.8

79.8

78.2

79.4

80.2

81.0

81.6

toxicity control

% degradation

ThOD = 181.4

mgO2/l

R1(tox1)

56.9

66.3

71.4

74.3

75.1

74.6

75.0

76.2

77.5

80.7

81.6

83.8

R2(tox2)

68.6

79.0

83.8

85.7

84.4

82.7

83.2

83.6

83.7

85.6

86.2

87.8

R3(tox3)

60.3

70.2

77.4

80.8

80.5

78.1

78.4

78.9

78.8

80.0

79.6

80.1

Rtoxavg

61.9

71.8

77.5

80.3

80.0

78.4

78.9

79.6

80.0

82.1

82.5

83.9

At 28 days of test performance:

- The aerobic biodegradation of methyltriacetoxysilane attained 79.5% of biodegradability (77.6% at 10 -day window).

- The aerobic biodegradation of the toxicity test reached 83.9% of biodegradation.

- The aerobic biodegradation of reference item sodium acetate reached 81.6% of biodegradability.

- The oxygen uptake of the inoculum blank was equal to 43.4 mg/dm3.

Conclusions:
The NOEC (28d) for microorganism toxicity of the test item methyltriacetoxysilane was determined to be 100 mg/L (based on biodegradation).
Executive summary:

A ready biodegradability manometic respirometry test was performed according to OECD Guideline 301 F. Test item methyltriacetoxysilane was incubated for 28 days at a concentration of 100 mg/L with 30 mg/L SS activated sludge inoculum under aerobic conditions in a mineral medium. Additionally, to check the possible inhibitory effect of the test item, a toxicity test run in parallele (100 mg/L test item with 100 mg/L reference subtance and 30 mg/L SS activated sludge inoculum) at same conditions. The NOEC (28d) of methyltriacetoxysilane was determined to be 100 mg/L since the substance degraded well (79.5% of biodegradation at 28 days) and did not inhibit the degradation of the toxicity test (83.9% of biodegradation after 28 days) up to 100 mg/L.

Endpoint:
toxicity to microorganisms, other
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment
Remarks:
No data on experimental method.
Principles of method if other than guideline:
No data on experimental method.
GLP compliance:
not specified
Remarks:
Data taken from a handbook where no information about experimental study is provided
Test organisms (species):
Pseudomonas sp.
Test type:
not specified
Water media type:
freshwater
Key result
Dose descriptor:
other: Toxicity
Effect conc.:
>= 630 mg/L
Remarks on result:
other: No data on duration

Butanone oxime was toxic to Pseudomonas sp at 630 mg/L.

Validity criteria fulfilled:
not specified
Conclusions:
Butanone oxime was toxic to Pseudomonas sp at 630 mg/L.
Executive summary:

Butanone oxime was toxic to Pseudomonas sp. at 630 mg/L.

Endpoint:
toxicity to microorganisms, other
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment
Remarks:
No data on experimental method.
Principles of method if other than guideline:
No data on experimental method.
GLP compliance:
not specified
Test organisms (species):
Photobacterium phosphoreum
Test type:
not specified
Water media type:
not specified
Key result
Duration:
5 min
Dose descriptor:
EC50
Effect conc.:
>= 955 mg/L
Validity criteria fulfilled:
not specified
Conclusions:
The 5 min-EC50 for Photobacterium phosphoreum was determined to be 955 mg/L.
Executive summary:

The 5 min-EC50 for Photobacterium phosphoreum was determined to be 955 mg/L.

Endpoint:
toxicity to microorganisms, other
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
Butan-2-one O,O',O''-(vinylsilanetriyl)oxime undergoes rapid hydrolysis in aqueous to butanone oxime and therefore, the observed toxicity to microorganisms is comparable.
See attached the reporting format.
Reason / purpose:
read-across source
Key result
Dose descriptor:
other: Toxicity
Effect conc.:
>= 755.63 mg/L
Remarks on result:
other: (Based on read-across approach from an analogue)
Validity criteria fulfilled:
not applicable
Conclusions:
Based on the read-across approach from analogue substance butanone oxime, butan-2-one O,O',O''-(vinylsilanetriyl)oxime
was determined to be toxic to Pseudomonas sp. at 755.63 mg/L.
Executive summary:

Based on the read-across approach from analogue substance butanone oxime, butan-2-one O,O',O''-(vinylsilanetriyl)oxime

was determined to be toxic to Pseudomonas sp. at 755.63 mg/L.

Endpoint:
toxicity to microorganisms, other
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
Butan-2-one O,O',O''-(vinylsilanetriyl)oxime undergoes rapid hydrolysis in aqueous to butanone oxime and therefore, the observed toxicity to microorganisms is comparable.
See attached the reporting format.
Reason / purpose:
read-across source
Key result
Duration:
5 min
Dose descriptor:
EC50
Effect conc.:
1 145.44 mg/L
Remarks on result:
other: (Based on read-across approach from an analogue)
Validity criteria fulfilled:
not applicable
Conclusions:
Based on the read-across approach form experimental results on analogue butanone oxime, the 5 min-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime in Photobacterium phosphoreum was determined to be 1101.52 mg/L.
Executive summary:

Based on the experimental results on analogue substance butanone oxime where the 5 min-EC50 for Photobacterium phosphoreum was determined to be 955 mg/L, the read-across approach was applied and the 5 min-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was determined to be 1145.44 mg/L.

Endpoint:
toxicity to microorganisms, other
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 methyltriacetoxysilane has a molecular structure similar to butan-2-one O,O',O''-(vinylsilanetriyl)oxime and therefore, they also have comparable values for the relevant molecular properties for toxicity to microorganisms.
Reason / purpose:
read-across source
Key result
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
142.32 mg/L
Nominal / measured:
estimated
Conc. based on:
other:
Remarks:
(analogue substance)
Basis for effect:
other: Biodegradation
Remarks on result:
other: (Based on read-across approach from an analogue)
Validity criteria fulfilled:
not applicable
Conclusions:
Based on the experimental results on analogue substance methyltriacetoxysilane, the read-across approach was applied and NOEC (28 d) for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be 142.32 mg/L.
Executive summary:

A ready biodegradability manometic respirometry test was performed according to OECD Guideline 301 F on analogue methyltriacetoxysilane and 28 day-NOEC was determined to be 100 mg/L since the substance was readily biodegradable (79.5% of biodegradation at 28 days) and did not inhibit the degradation of the toxicity test (83.9% of biodegradation after 28 days) up to 100 mg/L under aerobic conditions. Based on this results, the read-across approach was applied and 28 day-NOEC for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be 142.32 mg/L under test conditions.

Description of key information

Weight of evidence: Read-across from experimental results on butanone oxime: butan-2-one O,O',O''-(vinylsilanetriyl)oxime was determined to be toxic to Pseudomonas sp.at 755.63 mg/L.

Weight of evidence: Read-across from experimental results on butanone oxime the 5 min-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was determined to be 1145.44 mg/L.

Weight of evidence: Read-across from experimental results on methyltriacetoxysilane: The 28 day-NOEC for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be 142.32 mg/L under test conditions.

Weight of evidence: Read-across from experimental results on Wasox-VMAC2: the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 406.02 mg/L.

Weight of evidence: Read-across from experimental results on Wasox-MMAC2: the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 420.04 mg/L.

Key value for chemical safety assessment

EC50 for microorganisms:
406.02 mg/L
EC10 or NOEC for microorganisms:
142.32 mg/L

Additional information

The toxicity to microorganism is analized by the read-across approach from analogue substances:

- Read-across from experimental results on butanone oxime: By the read-across from butanone oxime, the toxicity to microorganism of the hydrolysis product of the test item is analysed and covered.

- Read-across from experimental results on analogue silanes: By the read-across from analogue silanes (methyltriacetoxysilane, Wasox-VMAC2 and Wasox-MMAC2), the toxicity to microorganism of the silane part of the substance is analysed and covered, since both test item Butan-2 -one O,O',O''-(vinylsilanetriyl)oxime, like methyltriacetoxysilane, Wasox-VMAC2 and Wasox-MMAC2, undergo rapid hydrolsyis in aqueous to corresponding silanols and at the same time, these silanols undergo continuous condensation reactions.

Read-across from experimental results on butanone oxime:

Weight of evidence: Based on the read-across approach from analogue substance butanone oxime, butan-2-one O,O',O''-(vinylsilanetriyl)oxime was determined to be toxic to Pseudomonas sp.at 755.63 mg/L.

Weight of evidence: Based on the experimental results on analogue substance butanone oxime where the 5 min-EC50 for Photobacterium phosphoreum was determined to be 955 mg/L, the read-across approach was applied and the 5 min-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was determined to be 1145.44 mg/L.

Read-across from experimental results on analogue silanes:

Weight of evidence: Based on the experimental results obtained in a ready biodegradability test (OECD 301F) performed on analogue methyltriacetoxysilane (28 day-NOEC = 100 mg/L), the read-across approach was applied and the 28 day-NOEC for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be 142.32 mg/L under test conditions.

Weight of evidence: Based on the experimental results obtained in an Activated Sludge, Respiration Inhibition Test (OECD 209) performed on analogue Wasox-VMAC2 (3h-EC50 > 300 mg/L, basis for effect: respiration rate), the read-across approach was applied and the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 406.02 mg/L.

Weight of evidence: Based on the experimental results obtained in an Activated Sludge, Respiration Inhibition Test (OECD 209) performed on analogue Wasox-MMAC2 (3h-EC50 > 300 mg/L, basis for effect: respiration rate), the read-across approach was applied and the 3h-EC50 for butan-2-one O,O',O''-(vinylsilanetriyl)oxime was calculated to be > 420.04 mg/L.