Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
biodegradation in water: screening tests
Type of information:
experimental study
Adequacy of study:
key study
Study period:
15.02.2000-April 2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study with acceptable restrictions
Qualifier:
according to
Guideline:
ECETOC Anaerobic Biodegradation (Technical Report No. 28)
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 311 (Anaerobic Biodegradability of Organic Compounds in Digested Sludge: Measurement of Gas Production)
GLP compliance:
no
Oxygen conditions:
anaerobic
Inoculum or test system:
digested sludge
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): digested sludge was collected from the Sjölunda municipal treatment plant (Malmö, Sweden)
- Laboratory culture: no
- Preparation of inoculum for exposure: the inoculum was washed twice with the medium, after the second wash, medium was added in order to obtain an inoculum with a content of 1 g/L suspended substance.
- Pretreatment: no
- Concentration of sludge: 1 g/L suspended substance
Duration of test (contact time):
62 d
Initial conc.:
24.4 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation:
CH4 evolution
Parameter followed for biodegradation estimation:
inorg. C analysis
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
The study was conducted according to ECETOC No. 28. Only a few details are reported. Deviations from the guideline were not reported.
TEST CONDITIONS
- Composition of medium: not reported
- Additional substrate: not reported
- Solubilising agent (type and concentration if used): not reported
- Test temperature: not reported
- pH: not reported
- pH adjusted: not reported
- Aeration of dilution water: no, test conducted under anaerobic conditions
- Suspended solids concentration: 1 g/L
- Continuous darkness: no

TEST SYSTEM
- Culturing apparatus: not reported
- Number of culture flasks/concentration: not reported (at least 12)
- Method used to create anaerobic conditions: not reported
- Measuring equipment: TIC: IR detector; CH4 and CO2: GC/TCD
- Test performed in closed vessels: yes
- Details of trap for CO2 and volatile organics if used: not reported

SAMPLING
- Sampling frequency: sampling was performed on day 0 and after 7, 22, 34, 43, and 62 d
- Sampling method: not reported
- Sample storage before analysis: not reported

CONTROL AND BLANK SYSTEM
- Inoculum blank: performed
- Toxicity control: performed
- Other: functional/procedural control performed
Reference substance:
benzoic acid, sodium salt
Test performance:
The study was conducted according to ECETOC Anaerobic Biodegradation (Technical Report No. 28). Deviations from guideline were not reported.
Parameter:
% degradation (DOC removal)
Value:
ca. 80
Sampling time:
62 d
Details on results:
Please refer to "Any other information on results incl. tables"
Results with reference substance:
The reference substance sodium benzoate was biodegradated by more than 70% in the course of the test (80% after 62 d; for details see above).

The study was conducted according to ECETOC Anaerobic Biodegradation (Technical Report No. 28). Deviations from guideline were not reported. The following results were obtained

1. TIC concentrations (mg/L) during degradation

Study day

Inoculum blank

Reference substance (control; a)

Test item

Toxicity control (b)

TIC reduction in relation to day 0

0

5.1

4.4

4.5

4.8

0

7

10.5

10.5

14.5

16.2

4.61

22

17.8

25.8

23.4

30.1

6.20

34

26.9

32.0

30.7

37.8

4.42

43

29.0

33.9

30.3

40.2

1.94

62

32.8

39.8

35.6

44.1

3.41

  1. bottle contains 40 mg/L sodium benzoate
  2. bottle contains test item and reference substance

2. Methane production during the test

Study day

Inoculum blank (mg C/L)

Reference substance (control; mg C/L; a)

Test item (mg C/L)

Toxicity control (mg C/L; b)

Test item-Inoculum blank (mg C/L)

0

-

-

-

-

-

7

5.5

9.7

21.4

23.9

15.87

22

13.4

25.3

27.5

36.1

14.06

34

24.7

33.4

37.3

49.4

12.55

43

27.1

40.6

41.3

54.4

14.16

62

34.2

43.3

45.3

58.8

11.05

a, b: see above

3. CO2production during the test

Study day

Inoculum blank (mg C/L)

Reference substance (control; mg C/L; a)

Test item (mg C/L)

Toxicity control (mg C/L; b)

Test item-Inoculum blank (mg C/L)

0

-

-

-

-

-

7

1.8

1.8

2.6

3.0

0.85

22

2.4

4.1

3.5

3.6

1.10

34

4.0

5.4

4.8

7.1

0.79

43

5.0

7.0

5.5

8.1

0.44

62

5.3

7.1

6.2

8.9

0.94

a, b: see above

4. Total amount of methane and carbon dioxide

Study day

TIC (mg C/L)

CH4 (mg C/L)

CO2 (mg C/L)

Σ(CH4 + CO2) (mg C/L)

Reduction of carbon in relation to day 0 (%)

0

-

-

-

-

-

7

4.61

15.9

0.85

21.3

87

22

6.20

14.1

1.10

21.4

88

34

4.42

12.6

0.79

17.9

73

43

1.94

14.2

0.44

16.5

68

62

3.41

11.1

0.94

15.4

63

The test item proved to be well biodegradable under anaerobic conditions (ca. 80% after 62 d). The reference substance sodium benzoate was biodegradated by more than 70% in the course of the test (80% after 62 d). In the toxicity control, an inhibitory effect of the test item on the anaerobic biodegradation was not observed.

Validity criteria fulfilled:
yes
Interpretation of results:
other: well biodegradable under anaerobic conditions
Conclusions:
The study was conducted according to ECETOC Anaerobic Biodegradation (Technical Report No. 28). Deviations from guideline were not reported. The test item proved to be well biodegradable under anaerobic conditions (ca. 80% after 62 d). The reference substance sodium benzoate was biodegradated by more than 70% in the course of the test (80% after 62 d). In the toxicity control, an inhibitory effect of the test item on the anaerobic biodegradation was not observed.
Executive summary:

The anaerobic biodegradability of C8 -18 AAPB was investigated in a study conducted according to ECETOC Anaerobic Biodegradation (Technical Report No. 28) over a period of 62 days and digested sludge as inoculum. The biodegradation rate was determined by measurement of gas production and TIC. Inoculum blank, procedural/functional control with the reference substance sodium benzoate and toxicity control were performed. Deviations from guideline were not reported.

This study is regarded as reliable with restrictions and satisfies the guideline requirements for anaerobic biodegradation.

The test item proved to be well biodegradable under anaerobic conditions (ca. 80% after 62 d). The functional control reached the pass level >70% (80% after 62 d). In the toxicity control containing both test and reference item an inhibitory effect of the test item on the anaerobic biodegradation was not observed.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
06.05.2008 to 04.06.2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): On May 5th, 2008, activated sludge was collected from the municipal wastewater treatment plant Breisgauer Bucht (Germany) which clarifies predominantly domestic wastewater.
- Laboratory culture: no
- Preparation of inoculum for exposure: The activated sludge was washed twice by settling the sludge, decanting the supernatant and re-suspending the sludge in aerated tap water.
- Pretreatment: no
- Concentration of sludge: 30 mg/L dry solids
Duration of test (contact time):
28 d
Initial conc.:
20 mg/L
Based on:
TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: mineral nutrient solution according to guideline
- Additional substrate: no
- Solubilising agent (type and concentration if used): no
- Test temperature: 20-22°C throughout the whole study
- pH: not reported
- pH adjusted: not reported
- Aeration of dilution water: yes
- Suspended solids concentration: 30 mg/L dry solids
- Continuous darkness: diffuse light

TEST SYSTEM
- Culturing apparatus: 2000 mL gas wash flasks
- Number of culture flasks/concentration: 3
- Method used to create aerobic conditions: The sealed test vessels filled with activated sludge and mineral medium were aerated with CO2-free air at a rate of 50-100 mL/min overnight.
- Measuring equipment: Toataol carbon analyzer TOC-5000A, Shimadzu Deutschland
- Test performed in closed vessels: yes
- Details of trap for CO2 and volatile organics if used: Two 250 mL gas wash bottles in series were used for CO2 absorption; each bottle was filled with 200 ml 0.2 M NaOH

SAMPLING
- Sampling frequency: sampling was performed at time 0 and after 3, 7, 10, 14, 21, 28, and 29 d (on day 28 1 mL concentrated HCl was added into each reactor to release the CO2 dissolved in water)
- Sampling method: at appointed times 4 mL NaOH from the first of two CO2-absorber flasks was sampled
- Sample storage before analysis: not reported

CONTROL AND BLANK SYSTEM
- Inoculum blank: performed
- Abiotic sterile control: not reported
- Toxicity control: not performed
- Other: functional/procedural control (reference substance) performed
Reference substance:
benzoic acid, sodium salt
Test performance:
The ready biodegradability of C8-18 AAPB was investigated in a study conducted according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test).
Parameter:
% degradation (CO2 evolution)
Value:
91.6
Sampling time:
28 d
Remarks on result:
other: the test substance proved to be readily biodegradable and fulfilling the 10-d window criterion
Results with reference substance:
The reference substance sodium benzoate was biodegraded by >90% after 7 d and thus fulfilling the guideline requirements.

The ready biodegradability of C8 -18 AAPB was investigated in a study conducted according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test). The results are compiled in the following tables.

Table 1: Ultimate biodegradation after x days (% of ThCO2)

Day

0

3

7

10

14

21

28

29*

Test flasks

1

2

3

0

0

0

32.7

41.9

43.3

73.0

74.2

77.3

85.6

84.6

82.6

93.4

93.8

90.8

103.7

101.5

99.4

96.8

93.9

92.4

94.3

92.6

87.9

Reference flasks

1

2

3

0

0

0

73.9

66.5

68.4

91.4

90.6

93.8

96.5

95.9

99.4

102.3

99.5

102.6

117.0

106.8

109.7

107.6

89.2

102.3

108.3

91.5

95.8

* after acidification

Table 2: Mean CO2-evolution of blank flasks after x days (mg/L)

Day

0

3

7

10

14

21

28

29*

CO2-evolution

0

6.4

14.0

18.8

23.7

27.1

30.0

34.6

* after acidification

C8 -18 AAPB proved to be readily biodegradable and fulfilling the 10 -d window criterion (91.6% biodegradation after 28 d). The reference substance sodium benzoate reached the pass-level of 60% ThCO2 by day 14. The IC content in the test vessel was <5% of the TOC introduced with the test material. The CO2 -evolution in the inoculum blank at the end of the test was below 40 mg/L. The difference of extremes of replicate values at the end of the 10 -d window and at the end of the test was <20%. The validity criteria of the guideline were fulfilled.

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
C8-18 AAPB proved to be readily biodegradable and fulfilling the 10 -d window criterion in a a study conducted according to OECD Guideline 301 B (91.6% biodegradation after 28 d).
Executive summary:

The ready biodegradation of C8 -18 AAPB was investigated in a study conducted according to OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test) over a period of 28 days and using activated sludge obtained from a municipal wastewater treatment plant as inoculum. The biodegradation rate was determined by measurement of CO2 -evolution. Inoculum blank and procedural/functional control with the reference substance sodium benzoateniline were performed. A toxicity control was not included in the study.

This study is regarded as reliable without restriction and satisfies the guideline requirements for ready biodegradation.

C8 -18 AAPB proved to be readily biodegradable and fulfilling the 10-d window criterion. The functional control reached the pass level >60% after 14 d.

Description of key information

Experimental results from several guideline studies (e. g. OECD 301 A, 301 B, 301 D, 301 E) on the aerobic biodegradation of Coco AAPB, C12 AAPB and C8-18 AAPB are available.
The inherent biodegradability of C12-18 AAPB was proven in a Zahn-Wellens Test. The anaerobic biodegradability of Coco AAPB and C8-18 AAPB was investigated in studies conducted similar to OECD guideline 311.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information

A CO2 Evolution Test as well as a Closed Bottle Test is available for the target substance C8 -18 AAPB. Moreover, an anaerobic biodegradation test is available. Further aerobic as well as anaerobic biodegradation screening tests are available for the source substance and C8-18 and C18 unsatd. AAPB (Coco AAPB). A justification for read-across is given in IUCLID section 5.2.

 

Aerobic biodegradation

Coco AAPB

A variety of different screening studies for Coco AAPB are available, confirming the readily biodegradability. One reliable study (Klimisch 1) was selected as key study and described in more detail.

 

The ready biodegradability of Coco AAPB was investigated in a study conducted according to EPA OPPTS 835.3120 (Sealed Vessel Carbon Dioxide Production Test) and ISO/DIS 14593 over a period of 28 days and using activated sludge as inoculum. The biodegradation rate was determined by measurement of CO2 evolution. Inoculum blank and procedural/functional control with the reference substance sodium benzoate performed.

Coco AAPB proved to be readily biodegradable and fulfilling the 10 -d window criterion (87.2% biodegradation after 28 d). The functional control reached the pass level >60% after 14 d.

 

Experimental results from several guideline studies (e. g. OECD 301 A, 301 B, 301 D, 301 E) on the aerobic biodegradation of Coco AAPB are available. The following results were obtained from studies fulfilling the validity criteria: (ISO/DIS 14593: 87.2 - 93 % biodegradation after 28 d; DOC Die-Away Test: 92 % degradation after 28 d; ; Closed-Bottle-Test: 86 % degradation after 28 d; Modified OECD Screening Test: 100 % biodegradation after 28 d). (Data are summariesed in an overview table in Annex I).

 

C12 AAPB

The ready biodegradability of C12 AAPB was investigated in a study conducted according to EU Method C.4-F (Determination of the "Ready" Biodegradability - MITI Test) over a period of 28 days and using an inoculum taken from a purifying plant for municipal and industrial effluents, from an industrial effluent purifying plant and surface water and surface soil from a river bank. The biodegradation rate was determined by measurement of oxygen consumption. Inoculum blank and procedural/functional controls with the reference substance sodium benzoate were performed. In deviation from guideline 2 instead of 3 bottles containing test material and inoculum were used. Furthermore, a bottle containing test substance in water only was not included in the tests. The test item proved to be readily biodegradable. After 28 days the percentage of biodegradability was 82 % based on ThOD (ThOD=0.7 mg O2/mg; ThOD not further specified: ThODNH4 or ThODNO3) and 95 % based on COD (COD=0.60 mg O2/mg). The functional control reached the pass level > 60 % after 14 d.

 

C12 -18 AAPB

The inherent biodegradation of C12 -18 AAPB was investigated in a study conducted according to DIN 38 412, Part 25 (1984) and which is equivalent or similar to OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test) over a period of 15 days and using non-adapted industrial activated sludge as inoculum. The substance proved to be inherently biodegradable (elimination: 90.8 % after 15 d; biodegradation: 89.4 % after 15 d). The adsorption to sludge was determined to 13 % after 3 h. The reference substance diethylene glycol was biodegraded by 96.6 % after 8 d. Based on these results it can be assumed that C12 -18 AAPB will be readily biodegradable in OECD Guideline tests on ready biodegradation. This assumption is supported by Zahn-Wellens tests with Coco AAPB where similar results were obtained and the ready biodegradability could be shown.

 

C8 -18 AAPB

C8 -18 AAPB proved to be readily biodegradable. In a study conducted according to OECD Guideline 301 B (Ready Biodegradability: CO2Evolution Test) over a period of 28 days and using activated sludge obtained from a municipal wastewater treatment plant as inoculum, the test substance was biodegraded by 91.6 % after 28 d (10 d window criterion fulfilled). These results were supported by a further guideline study. In a supporting study conducted according to EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test), the test substance was biodegraded by 76.3 % after 28 d).

 

Anaerobic biodegradation

The anaerobic biodegradability of Coco AAPB was investigated in a study conducted according to ISO11734 (Water quality - Evaluation of the ultimate anaerobic biodegradability of organic compounds in digested sludge - Method by measurement of the biogas production) and equivalent or similar to OECD Guideline 311 (Anaerobic Biodegradability of Organic Compounds in Digested Sludge: Measurement of Gas Production) over a period of 60 days and using non-adapted digester sludge as inoculum. The biodegradation rate was determined by measurement of total biogas production. Inoculum blank and procedural/functional controls with the reference substance polyethylene glycol 400 were performed. The test item proved to be biodegradable under anaerobic conditions (total biodegradation: 80-90 % after 60 d). The functional control reached the pass level > 60 % after 60 d.

 

In a second study the anaerobic biodegradability of C8 -18 AAPB was investigated in a study conducted according to ECETOC Anaerobic Biodegradation (Technical Report No. 28; similar to OECD guideline 311) over a period of 62 days and digested sludge as inoculum.The biodegradation rate was determined by measurement of gas production and TIC. Inoculum blank, procedural/functional control with the reference substance sodium benzoate and toxicity control were performed. Deviations from guideline were not reported.

The test item proved to be well biodegradable under anaerobic conditions (ca. 80% after 62 d).The functional control reached the pass level >70% (80% after 62 d). In the toxicity control containing both test and reference item an inhibitory effect of the test item on the anaerobic biodegradation was not observed.

 

Conclusion

Experimental results from several guideline studies (e. g. OECD 301 A, 301 B, 301 D, 301 E) on the aerobic biodegradation of Coco AAPB, C12 AAPB and C8 -18 AAPB are available. Based on the results, Coco AAPB, C12 AAPB, and C8 -18 AAPB can be regarded as readily biodegradable. The inherent biodegradability of C12-18 AAPB was proven in a Zahn-Wellens Test. Based on these results, the AAPBs can be regarded as readily biodegradable.

The anaerobic biodegradability of Coco AAPB and C8-18 AAPB was investigated in studies conducted similar to OECD guideline 311. Based on the results of these studies, the AAPBs are considered to be biodegradable under anaerobic condition.