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Environmental fate & pathways

Biodegradation in water: screening tests

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Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
13 May - 11 Jun 1997
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP-Guideline study with acceptable restrictions: No purity of the test substance is given. A temporary breakdown (≤ 1 day) in the aeration was observed on day 28. However, this breakdown is considered to have no effect on the outcome of this study.
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
yes
Remarks:
A temporary breakdown (≤ 1 day) in the aeration was observed on day 28.
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: Municipal sewage treatment plant: Waterschap de Maaskant, s'Hertogenbosch, The Netherlands
- Preparation of inoculum for exposure: Before use, the sludge was allowed to settle for at least 30 min and the liquid was decanted for use as inoculum at the amount of 10 mL/L of mineral medium.
- Pretreatment: The sludge was kept under continuous aeration until further treatment.
- Initial cell/biomass concentration: From the supernatant of the sludge the heterotrophic microbial colony count was determined to be 6.6 x 10³ cells/mL. Since 10 mL supernatant was added per litre of mineral medium, the test system contained 0.7 x 10² cells/mL.
Duration of test (contact time):
29 d
Initial conc.:
15.5 - 15.6 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: Mineral medium
- Test temperature: 20 - 21.5 °C
- pH: 7.5 - 7.9
- Aeration of dilution water: The mixture of mineral components, Milli-Q water and inoculum was aerated with CO2-free air overnight to purge the system of CO2.
- Suspended solids concentration: 4.1 g/L

TEST SYSTEM
- Culturing apparatus: 2 litre all-glass brown coloured bottles
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: CO2-free air was sparged through the scrubbing solutions at a constant rate.
- Details of trap for CO2: Three CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2) were connected in series to the exit air line of each test bottle. The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate.

SAMPLING
- Sampling frequency: Samples were taken on day 3, 6, 8, 10, 15, 20, 24 and 29.
- Sampling method: The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0.05 M standardized HCl. On the 28th
day, the pH of the test suspensions was measured and 1 mL of concentrated HCl was added to each bottle. The bottle were aerated overnight to
drive off CO2 present in the test suspension. The final titration was made on day 29.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 2 replicates
- Toxicity control: yes, 1 replicate
Reference substance:
acetic acid, sodium salt
Parameter:
% degradation (CO2 evolution)
Value:
66.4 - 73.3
Sampling time:
29 d
Details on results:
Within the 10-day time window the 60% level was not passed. Therefore the conclusion of the study report was "not readily biodegradable". As the test substance is a mixture of constituents with different chain-lengths, sequential (instead of concurrent) biodegradation takes place. Thus, referring to Annex I to the OECD Guideline for The Testing of Chemicals 'Revised introduction to the OECD guidelines for testing of chemicals, section 3' (OECD, March 2006), the 10 -day-window should not be considered for the test substance. Due to a degradation of > 60% within 28 days the test substance can be regarded as readily biodegradable.
Results with reference substance:
Degradation: 67.9% after 10 days, 60% pass level was reached.

A temporary breakdown (≤ 1 day) in the aeration was noted on day 28. However, this breakdown was considered to have no effect on the outcome of this study.

The toxicity control showed an biodegradation of > 25% (80.6%) indicating that the test substance do not have an inhibitory effect on aquatic microorganisms.

Table 1: Percentage biodegradation of test substance, reference substance and toxicity control

Day

Test substance [% degradation]

Reference substance [% degradation]

Toxicity control [% degradation]

Replicate 1

Replicate 2

Ø

3

0.7

0.3

0.50

14.6

10.6

6

1.6

3.9

2.75

42.1

22.3

8

10.5

14.3

12.40

58.9

31.3

10

20.1

22.4

21.25

67.9

36.0

15

33.5

43.2

38.35

72.7

52.7

20

45.1

53.5

49.30

79.7

64.9

24

52.0

60.0

56.00

81.2

66.6

29

64.2

69.7

66.95

87.6

77.0

29

65.1

71.9

68.50

90.8

79.3

29

66.4

73.3

69.85

93.2

80.6

 

 

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
12 Sep - 10 Oct 2006
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
no
GLP compliance:
no
Remarks:
The study was conducted in accordance with ISO/IEC 17025
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: Activated sludge from the aeration tank of the municipal waste water treatment plant ARA Werdhölzli, 8048 Zürich, Switzerland; collected 6 Sep 2006, 2:00 pm
- Preparation of inoculum for exposure: Prior to the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L of suspended solids
Duration of test (contact time):
28 d
Initial conc.:
23 - 23.2 mg/L
Based on:
other: TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: mineral medium (according to OECD guideline 301) prepared with deionized water
- Test temperature: 22 ± 0.5 °C
- pH: 7.4 ± 0.2
- pH adjusted: yes
- Aeration of dilution water: yes
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottles containing 2000 mL test solution
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The test vessels were stirred (100 rpm) and aerated with synthetic CO2-free air.
- Details of trap for CO2 and volatile organics if used: Gas-absorption bottles containing 125 mL of 0.13 M KOH

SAMPLING
- Sampling frequency: Samples for CO2 measurements were taken after 1, 3, 7, 10, 14, 17, 21, 24 and 28 days exposure time.
- Sampling method: The samples from the individual test vessels were centrifuged (15 min at 4500 g) and acidified to pH < 2. Prior to analysis the samples were sparged with CO2-free high purity air for 10 min to remove inorganic carbon. The traped CO2 was determined as inorganic carbon (IC). IC was determined in the same way as DOC without sparging the samples before analysis.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Inoculum and test medium: 2 replicates
Reference substance:
benzoic acid, sodium salt
Remarks:
20 mg/L TOC
Parameter:
% degradation (CO2 evolution)
Value:
79.5
Sampling time:
28 d
Remarks on result:
other: Average of two replicates (74.8%, 84.2%)
Details on results:
Due to the limit water solubility of the test substance, biodegradation based on DOC measurements was not assessed.
The test substance reached the pass level of 60% for ready biodegradability within the 10-d window and therefore, can be judged as readily biodegradable according to OECD criteria.
Results with reference substance:
Sodium benzoate showed a degradation of 91.3% after 28d exposure time.

Table 1: CO2 produced by the test units, the inoculum blank and the corresponding degradation data

 

Inoculum blank

Test unit no.1

Test unit no. 2

 

Time [d]

Total CO2 release in test sample [mg IC/L]

Total CO2 release in test sample [mg IC/L]

Degradation [%]

Total CO2 release in test sample [mg IC/L]

Degradation [%]

Mean Degradation of no. 1+2 [%]

0

0.0

0.0

0.0

0.0

0.0

0.0

1

0.0

0.0

0.1

-0.1

-0.4

-0.2

3

0.8

3.3

11.1

2.6

8.1

9.6

7

1.9

10.5

37.0

8.9

30.4

33.7

10

2.8

15.7

55.7

13.8

47.7

51.7

14

2.8

19.1

70.3

15.9

56.7

63.5

17

2.7

20.1

75.2

17.2

63.2

69.2

21

3.5

21.8

79.2

19.3

68.7

73.9

24

3.5

22.3

81.1

19.8

70.9

76.0

28

3.8

23.3

84.2

21.0

74.8

79.5

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
17 Oct - 14 Nov 2006
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
no
GLP compliance:
no
Remarks:
But conducted in accordance with ISO/IEC 17025
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: activated sludge from the aeration tank of the municipal waste water treatment plant ARA Werdhölzli, CH-8048 Zürich, collected: 11 Oct 2006, 10:00 a.m.
- Preparation of inoculum for exposure: Prior to the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L of suspended solids
Duration of test (contact time):
28 d
Initial conc.:
19.5 - 19.7 mg/L
Based on:
other: TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: aerobic mineral salts medium (according to OECD guideline 301) prepared with deionised water
- Test temperature: 22 ± 0.5 °C
- pH: 7.4 ± 0.2
- pH adjusted: yes, if necessary with NaOH or HCl
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottles containing a total volume of test solution of 2000 mL
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The test vessels were stirred (100 rpm) and aerated with synthetic CO2-free air over the whole test period.
- Measuring equipment: Dissolved organic carbon (DOC) was determined with a Shimadzu 5050 TOC-Analyzer using the NPOC-mode. TOC was determined with a TOC-Analyzer by an external laboratory.
- Details of trap for CO2 and volatile organics if used: Test vessels fitted to gas-absorption bottles containing 125 mL of 0.13 M KOH. The trapped CO2 was determined as inorganic carbon (IC).

SAMPLING
- Sampling frequency: Samples were taken 0, 1, 3, 7, 10, 14, 21, 24 and 28 days.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 1
Parameter:
% degradation (CO2 evolution)
Value:
85
Sampling time:
28 d
Remarks on result:
other: average of two replicates
Details on results:
The test substance reached 72% biodegradation within the 10-d window. Therefore, the test substance can be considered as readily biodegradable according to OECD criteria.

Table 1: CO2 produced by the test units, the inoculum blank and the corresponding degradation data

 

Inoculum blank*

Test unit 1

Test unit 2

 

Time[d]

Total CO2 release in test sample [mg IC/L]

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Mean Degradation of test unit 1 +2 [%]

0

0.0

0.0

0.0

0.0

0.0

0.0

1

0.0

0.1

0.3

0.2

0.8

0.5

3

0.2

2.4

10.8

2.8

12.8

11.8

7

2.3

10.7

43.1

11.1

44.5

43.8

10

3.4

15.2

60.5

15.2

59.6

60.1

14

5.7

20.5

75.7

21.3

79.2

77.5

21

7.6

23.6

82.8

24.5

85.7

83.9

24

8.8

24.7

81.5

25.6

85.3

83.4

28

9.4

25.7

83.9

26.2

85.6

84.7

* Mean of two replicates

** The calculation is based on an organic carbon concentration in mg/L of 19.5 (test unit 1) and 19.7 (test unit 2).

Due to the limited water solubility of the test substance, biodegradation based on DOC measurements was not assessed.

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
17 Oct - 14 Nov 2006
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
GLP compliance:
no
Remarks:
But conducted in accordance with ISO/IEC 17025
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: activated sludge from the aeration tank of the municipal waste water treatment plant ARA Werdhölzli, CH-8048 Zürich, collected: 11 Oct 2006, 10:00 a.m.
- Preparation of inoculum for exposure: Prior to the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L of suspended solids
Duration of test (contact time):
28 d
Initial conc.:
20.2 mg/L
Based on:
other: TOC
Details on study design:
TEST CONDITIONS
- Composition of medium: aerobic mineral salts medium (according to OECD guideline 301) prepared with deionised water
- Test temperature: 22 ± 0.5 °C
- pH: 7.4 ± 0.2
- pH adjusted: yes, if necessary with NaOH or HCl
- Suspended solids concentration: Final test concentration = 18.9 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottles containing a total volume of test solution of 2000 mL
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The test vessels were stirred (100 rpm) and aerated with synthetic CO2-free air over the whole test period.
- Measuring equipment: Dissolved organic carbon (DOC) was determined with a Shimadzu 5050 TOC-Analyzer using the NPOC-mode. TOC was determined with a TOC-Analyzer by an external laboratory.
- Details of trap for CO2 and volatile organics if used: Test vessels fitted to gas-absorption bottles containing 125 mL of 0.13 M KOH. The trappüed CO2 was determined as inorganic carbon (IC).

SAMPLING
- Sampling frequency: Samples were taken 0, 1, 3, 7, 10, 14, 21, 24 and 28 days.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 1
Parameter:
% degradation (CO2 evolution)
Value:
78
Sampling time:
28 d
Remarks on result:
other: Average of 2 replicates
Details on results:
The test substance reached the pass level of 60% for ready biodegradability within the 10-d window. Therefore, the test substance can be considered as readily biodegradable.

Table 1: CO2 produced by the test units, the inoculum blank and the corresponding degradation data

 

Inoculum blank*

Test unit 1

Test unit 2

 

Time[d]

Total CO2 release in test sample [mg IC/L]

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Mean Degradation of test unit 1 +2 [%]

0

0.0

0.0

0.0

0.0

0.0

0.0

1

0.0

0.3

1.3

0.3

1.5

1.4

3

0.2

2.4

10.8

1.6

6.5

8.7

7

2.3

10.6

40.9

10.6

41.2

41.1

10

3.4

14.5

54.7

14.6

55.5

55.1

14

5.7

18.7

64.1

20.8

75.0

69.5

21

7.6

22.6

74.3

23.9

81.2

77.7

24

8.8

23.7

73.7

24.6

78.7

76.2

28

9.4

25.0

77.1

25.3

79.1

78.1

* Mean of two replicates

** The calculation is based on an organic carbon concentration in mg/L of 20.2 (test unit 1) and 20.1 (test unit 2).

Due to the limited water solubility of the test substance, biodegradation based on DOC measurements was not assessed.

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
9 Feb - 9 Mar 2006
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
no
GLP compliance:
no
Remarks:
But conducted in accordance with ISO/IEC 17025
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: activated sludge from the aeration tank of the municipal waste water treatment plant ARA Werdhölzli, CH-8048 Zürich, collected: 6 Feb 2006, 11:00 a.m.
- Preparation of inoculum for exposure: Prior to the test the sludge was washed twice with tap water.
- Concentration of sludge: 30 mg/L of suspended solids
Duration of test (contact time):
28 d
Initial conc.:
18.9 mg/L
Based on:
other: TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: aerobic mineral salts medium (according to OECD guideline 301) prepared with deionised water
- Test temperature: 22 ± 0.5 °C
- pH: 7.4 ± 0.2
- pH adjusted: yes, if necessary with NaOH or HCl
- Suspended solids concentration: Final test concentration = 18.9 mg/L
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 2500 mL closed glass bottles containing a total volume of test solution of 2000 mL
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: The test vessels were stirred (100 rpm) and aerated with synthetic CO2-free air over the whole test period.
- Measuring equipment: Dissolved organic carbon (DOC) was determined with a Shimadzu 5050 TOC-Analyzer using the NPOC-mode. TOC was determined with a TOC-Analyzer by an external laboratory.
- Details of trap for CO2 and volatile organics if used: Test vessels fitted to gas-absorption bottles containing 125 mL of 0.13 M KOH. The trappüed CO2 was determined as inorganic carbon (IC).

SAMPLING
- Sampling frequency: Samples were taken 0, 1, 4, 7, 11, 14, 18, 21, 25 and 28 days.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 1
Reference substance:
benzoic acid, sodium salt
Remarks:
20.1 mg/L as TOC
Parameter:
% degradation (CO2 evolution)
Value:
81
Sampling time:
28 d
Remarks on result:
other: Average of 2 replicates
Details on results:
The test substance reached the pass level of 60% for ready biodegradability within the 10-d window. Therefore, the test substance can be considered as readily biodegradable.
Results with reference substance:
Sodium benzoate reached 93% biodegradation after 14 days, thus confirming the suitability of inoculum and test conditions.

Table 1: CO2 produced by the test units, the inoculum blank and the corresponding degradation data

 

Inoculum blank*

Test unit 1

Test unit 2

 

Time [days]

Total CO2 release in test sample [mg IC/L]

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Total CO2 release in test sample [mg IC/L]

Degradation [%]**

Mean Degradation of test unit 1 +2 [%]

0

0.0

0.0

0.0

0.0

0.0

0.0

1

0.2

0.1

-0.6

0.1

-0.2

-0.4

4

1.8

5.6

19.8

4.5

14.0

16.9

7

2.3

11.4

48.1

9.0

35.7

41.9

11

3.4

16.0

66.4

14.2

56.8

61.6

14

3.8

17.5

72.5

17.0

69.6

71.0

18

4.9

20.1

80.5

19.5

77.1

78.8

21

5.2

20.6

81.5

20.4

80.0

80.7

25

6.1

20.6

76.9

21.4

81.0

79.0

28

6.2

21.1

78.9

21.9

82.9

80.9

* Mean of two replicates

** The calculation is based on an organic carbon concentration in mg/L of 18.9 (test unit 1 and 2)

Due to the limited water solubility of the test substance, biodegradation based on DOC measurements was not assessed.

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Remarks:
Summary of available data used for the endpoint assessment of the target substance
Adequacy of study:
key study
Justification for type of information:
Please refer to the analogue justification attached to IUCLID section 13.
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Reason / purpose:
read-across source
Parameter:
% degradation (CO2 evolution)
Value:
85
Sampling time:
28 d
Remarks on result:
other: average of two replicates
Remarks:
RA-A from CAS 95912-89-3, Oleon, 2006a
Parameter:
% degradation (CO2 evolution)
Value:
78
Sampling time:
28 d
Remarks on result:
other: average of two replicates
Remarks:
RA-A from CAS 95912-89-3, Oleon, 2006b
Parameter:
% degradation (CO2 evolution)
Value:
81
Sampling time:
28 d
Remarks on result:
other: average of two replicates
Remarks:
RA-A from CAS 95912-89-3, Oleon, 2006c
Parameter:
% degradation (CO2 evolution)
Value:
> 66.4 - < 73.3
Sampling time:
29 d
Remarks on result:
other: RA-A from CAS 95912-89-3, Croda, 1997
Parameter:
% degradation (CO2 evolution)
Value:
79.5
Sampling time:
28 d
Remarks on result:
other: average of two replicates
Remarks:
RA-A from CAS 91001-61-5, Oleon, 2006d
Parameter:
other: infrared spectroscopy
Value:
> 95
St. dev.:
5
Sampling time:
21 d
Remarks on result:
other: supporting RA-A from CAS 91001-61-5, Oleon, 1991
Parameter:
% degradation (CO2 evolution)
Value:
60.9
Sampling time:
28 d
Remarks on result:
other: supporting RA-A from CAS 91001-61-5, Oleon, 2003
Endpoint:
biodegradation in water: screening tests
Type of information:
experimental study
Adequacy of study:
supporting study
Study period:
1991
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Only short abstract available
Qualifier:
according to
Guideline:
other: CEC L-33-T-82
GLP compliance:
not specified
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge: activated sludge from domestic wastewater treatment plant Wavre
- Initial cell/biomass concentration: > 10E6 CFU/mL
Duration of test (contact time):
21 d
Parameter followed for biodegradation estimation:
other: infrared spectroscopy
Parameter:
other: infrared spectroscopy
Value:
> 95
St. dev.:
5
Sampling time:
21 d
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
other: Only short abstract available
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
not specified
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge: Activated sludge obtained from wastewater treatment plant Wavre 2nd Stage
- Initial cell/biomass concentration: > 10E6 CFU/mL (verified with Merck Cult Dip Combi)
Duration of test (contact time):
28 d
Initial conc.:
20 mg/L
Based on:
other: TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Test temperature: 20.8 - 21.4 °C
- pH: start: 7.4; end: 6.5
Reference substance:
benzoic acid, sodium salt
Remarks:
3 g/L
Parameter:
% degradation (CO2 evolution)
Value:
60.9
Sampling time:
28 d

Description of key information

Based on the results from the similar read-across substances, the target substance Fatty acids, C8-10-(even numbered), esters with pentaerythritol and adipic acid (EC 948-383-1) can be considered readily biodegradable according to OECD criteria.

Key value for chemical safety assessment

Additional information

No study is available in which the ready biodegradability of Fatty acids, C8-10-(even numbered), esters with pentaerythritol and adipic acid (EC 948-383-1) was assessed. Therefore, read-across to the following structurally and chemically closely related source substances was performed in accordance with Regulation (EC) No 1907/2006 Annex XI, section 1.5 in order to fulfill the data requirements for this substance: Fatty acids, C8-10, mixed esters with adipic acid and trimethylolpropane (CAS 95912-89-3), 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8), and Fatty acids, C16-18 and C18-unsatd., mixed esters with adipic acid and trimethylolpropane (CAS 91001-61-5). The source substances are characterized by similar chemical structure and are therefore considered suitable representatives for the assessment of the ready biodegradability of the target substance. A detailed read-across justification in provided in IUCLID section 13.

Three studies are available for the source substance Fatty acids, C8-10, mixed esters with adipic acid and trimethylolpropane (CAS 95912-89-3). All three studies were performed according to OECD guideline 301B (CO2Evolution Test) under aerobic conditions and used activated, domestic, non-adapted sludge as inoculum. The studies were not performed under GLP but in accordance with ISO/IEC 17025. The initial test concentration was between 18.9 and 20.2 mg/L (based on TOC) across the three studies. After 28 d, biodegradation rates of 78-85% (based on CO2evolution) were observed. The 60% pass level of the 10-day-window was fulfilled. The source substance Fatty acids, C8-10, mixed esters with adipic acid and trimethylolpropane (CAS 95912-89-3) can therefore be considered readily biodegradable according to OECD criteria.

One study is available for the source substance 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8). The study was performed under GLP according to OECD guideline 301B (CO2Evolution Test). The study was performed under aerobic conditions and used activated, domestic, non-adapted sludge as inoculum. Two test solutions with initial test item concentrations of 15.5 and 15.6 mg/L (based on test material) were prepared. After 29 days, biodegradation rates of 66.4-73.3% (based on CO2evolution) were observed. Since the test item is a UVCB substance and consists of structurally similar constituents with different chain-lengths, sequential (instead of concurrent) biodegradation of the individual structures can take place, but all can be considered as readily biodegradable. Thus, referring to Annex I to the OECD Guideline for Testing of Chemicals ‘Revised introduction to the OECD guidelines for testing of chemicals, section 3’ (OECD, March 2006), the 10-day window should not be considered for UVCB substances, and due to a degradation of >60 % within 28 days the source substance 2,2-bis[[(1-oxoisooctadecyl)oxy]methyl]-1,3-propanediyl bis(isooctadecanoate) (CAS 62125-22-8) can be regarded as readily biodegradable according to OECD criteria.

Three studies are available for the source substance Fatty acids, C16-18 and C18-unsatd., mixed esters with adipic acid and trimethylolpropane (CAS 91001-61-5). For two of the three studies, the available information was not sufficient to be used as weight-of-evidence information and are therefore considered supporting studies. The third study can be considered weight-of-evidence information and was conducted as non-GLP study according OECD guideline 301B (CO2Evolution Test). The study was performed under aerobic conditions and used activated, non-adapted sludge as inoculum. Two test solutions with initial test item concentrations of 23.0-23.2 mg/L (based on TOC) were prepared. After 28 d, biodegradation rates of 74.8-84.2% (based on CO2evolution) were observed. The 60% pass level of the 10-day-window was fulfilled. The source substance Fatty acids, C16-18 and C18-unsatd., mixed esters with adipic acid and trimethylolpropane (CAS 91001-61-5) can therefore be considered readily biodegradable according to OECD criteria.

Only little information from a short abstract is available for the two supporting studies on the read-across substance Fatty acids, C16-18 and C18-unsatd., mixed esters with adipic acid and trimethylolpropane (CAS 91001-61-5). One study was conducted according to OECD Guideline 301B (CO2 evolution) under aerobic conditions using activated domestic sludge as inoculum. A test solution of 20 mg/L initial test substance concentration (based on TOC) was prepared. After 28 d, a biodegradation rate of 60.9% (based on CO2evolution) was observed. The second supporting study was conducted according to guideline CEC L-33-T-82. under aerobic conditions using activated domestic sludge as inoculum. After 21 d, a biodegradation rate of >95% (determined by IR spectroscopy) was observed.

Based on the available results from structurally related read-across substances (in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5) which are characterized by a similar ecotoxicological profile and comparable structure, it can be concluded that the target substance Fatty acids, C8-10-(even numbered), esters with pentaerythritol and adipic acid (EC 948-383-1) is readily biodegradable.