Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The test was carried out in accordance with the OECD Guideline for Testing of Chemicals No. 301 F.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2000
Report Date:
2000

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Swiss Federal Department of the Interior

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Triol
- Physical state: white solid
- Analytical purity: 99.5 % (LC), 99.8 % (DSC)
- Lot/batch No.: 6262/ZTN/03/N/08/001/003
- Expiration date of the lot/batch: 1 December 2000
- Stability under test conditions: not specified in water
- Storage condition of test material: in refridgerator at 4 +/- 3 °C, protected from sunlight
- Other:

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Wastewater treatment plant ARA Ergolz II, Füllinsdorf, Swtizerland
- Laboratory culture:
- Method of cultivation:
- Storage conditions: aerated at room temperature
- Storage length:
- Preparation of inoculum for exposure:
- Pretreatment:
- Concentration of sludge: 1 g/L (dry weight basis), which was then diluted to give a final concentration in the inoculum of 30 mg dry weight per liter
- Initial cell/biomass concentration:
- Water filtered: yes/no
- Type and size of filter used, if any:
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: a) 8.5 g KH2PO4, 21.75 g K2HPO4, 33.4 g Na2HPO4 x 2 H2O, 0.5 g NH4Cl dissolved in purified water and made up to 1000 mL (pH 7.4); b) 22.5 g MgSO4 x 7 H2O dissolved in purified water and made up to 1000 mL; c) 36.4 g CaCl2 x 2H2O dissolved in purified water and made up to 1000 mL; d) 0.25 g FeCl3 X 6 H2O dissolved in purified water and made up to 1000 mL (in order to avoid having to prepare this solution immediately before use, a drop of concentration HCl per liter was added). The final test water was obtained by mixing 10 mL of solution a) and 1 mL each of solutions b)-d) and making up to 1000 mL with purified water. pH was adjusted to 7.4 with a diluted hydrochloric acid solution.
- Additional substrate:
- Solubilising agent (type and concentration if used):
- Test temperature: 22 °C
- pH: 7.4 at the start of the test
- pH adjusted: yes
- CEC (meq/100 g):
- Aeration of dilution water:
- Suspended solids concentration: 30 mg dry material per liter
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus:
- Number of culture flasks/concentration: two
- Method used to create aerobic conditions: electrolytically generated oxygen from a copper sulfate solution
- Method used to create anaerobic conditions:
- Measuring equipment: electrode type manometer
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Details of trap for CO2 and volatile organics if used:
- Other:


SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes
- Other: Procedure control


STATISTICAL METHODS:
Reference substance
Reference substance:
other: Sodium benzoate

Results and discussion

Preliminary study:
The biochemical oxygen demand (BOD) of the test article Triol in the test media was within the range of the inoculum controls. Consequently, Triol was found to be not biodegradable under the test conditions within 28 days.
Test performance:
The results with the positive reference substance indicated the suitability of the activated sludge.
% Degradation
Parameter:
% degradation (O2 consumption)
Value:
1
Sampling time:
28 d
Details on results:
Details are given in Table 1
The biodegradation rate in the toxicty control showed a similar course of biodegradation over the 28 days of exposure as the two procedure controls containing the reference item only. Within 14 days of exposure a biodegradation of 38 % was observed. Thus, according to the test guidelines, the test item had no inhibitory effect on activated sludge microorganisms as the biodegradation rate in the toxicity control was > 25 % after 14 days.

BOD5 / COD results

Results with reference substance:
In the procedure controls, the reference item sodium benzoate was degraded by an average of 84 % by exposure day 14, thus confirming the suitability of the activated sludge. At the end of the test (day 28), the reference item was degraded by an average of 89 %.

Any other information on results incl. tables

Table 2: Biodegradation of Triol and the reference item.

Time (days)

Percentage biodegradation (corrected for inoculum controls)

Test item

Procedure control

Toxicity control

Flask No. 5

Flask No. 6

Flask No. 3

Flask No. 4

Flask No. 8

0

0

0

0

0

0

1

0

0

10

7

3

2

1

0

49

49

19

3

0

0

57

57

22

4

-

-

-

-

-

5

-

-

-

-

-

6

0

0

73

78

33

7

1

0

76

80

33

8

1

0

78

81

34

9

1

0

79

82

35

10

1

0

80

83

35

11

-

-

-

-

-

12

-

-

-

-

-

13

1

0

82

85

37

14

1

0

83

85

38

15

1

0

83

86

38

16

1

0

84

87

39

17

1

0

84

87

40

18

-

-

-

-

-

19

-

-

-

-

-

20

1

0

85

88

41

21

1

0

85

88

41

22

1

0

85

88

42

23

1

0

86

89

42

24

2

0

86

89

43

25

-

-

-

-

-

26

2

0

87

90

44

27

2

0

87

90

45

28

2

1

88

91

46

Mean (Day 28)

1

89

- not determined

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Triol was found to be not biodegradable under the test conditions within 28 days.
Executive summary:

The test item Triol was investigated for its ready biodegradability in a 28 -day manometric respiratory test based on Commission Directive 92/69/EEC, C.4 -D, 1992, and OECD Guideline No. 301 F, 1992.

The biochemical oxygen demand (BOD) of Triol in the test media was within the range of the inoculum control.

Consequently, Triol was found to be not biodegradable under the test conditions within 28 days.

In the toxicity control, containing both Triol and the reference item sodium benzoate, no inhibitory effect on the biodegradation of the reference item was determined. Thus, Triol had obviously no inhibitory effect on the activity of activated sludge microorganisms.

In the procedure controls, the reference item sodium benzoate was biodegraded by an average of 84 % after two weeks, and reached an average biodegradation rate of 89 % by the end of the tes, thus confirming the suitability of the activated sludge.