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Administrative data

Endpoint:
biodegradation in soil: simulation testing
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because the substance is readily biodegradable
Cross-reference
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
30 July - 10 October 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Deviations:
no
Principles of method if other than guideline:
Not applicable
GLP compliance:
yes (incl. QA statement)
Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of activated sludge: Wastewater treatment plant (ARA Ergolz II, Füllinsdorf, Switzerland) treating predominantly domestic wastewater
- Preconditioning: The sludge was washed twice with tap water by centrifugation and the supernatant liquid phase was decanted. During the holding period of one day prior to use, the sludge was aerated at room temperature.
- Dry weight of suspended solids: 4 g/L
- Concentration of sludge in test water: 30 mg dry material/L
Duration of test (contact time):
ca. 28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: Nutrient medium contained per litre of deionised water: 85 mg KH2PO4, 217.5 mg K2HPO4, 334 mg Na2HPO4.2H2O, 5 mg NH4Cl, 22.5 mg MgSO4.7H2O, 36.4 mg CaCI2.2H2O, 0.25 mg FeCI3.6H2O
- Source/preparation of dilution water: Purified water
- Test temperature: 22 °C, maintained with a built-in thermostat and checked at least on each working day.
- pH: 7.3-7.4 (at the start of the test); 7.5–8.4 (at the end of test)
- pH adjusted: Yes, pH was adjusted from 7.9 to 7.4 with a diluted hydrochloric acid solution.
- Continuous darkness: Yes

TEST SYSTEM
- Culturing apparatus: Flasks (500 mL)
- Number of culture flasks/concentration: Two for test item, inoculum and procedure control and one for toxicity control
- Measuring equipment: SAPROMAT D12 (Voith GmbH, Heidenheim, Germany)
- Details of trap for CO2: Evolved CO2 was absorbed by soda lime

SAMPLING
- Sampling frequency: Oxygen consumption was recorded manually by taking a daily reading at least on each working day. The pH was measured in each test flask before the addition of the activated sludge inoculum and at the end of incubation.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes; containing inoculum only
- Procedure control: Yes; containing reference substance (sodium benzoate) with inoculated medium
- Toxicity control: Yes; containing test material and reference substance (sodium benzoate) with inoculated medium
Reference substance:
benzoic acid, sodium salt
Remarks:
100 mg/L; purity: 99.7 %; source: Sigma-Aldrich
Preliminary study:
No data
Test performance:
No data
Key result
Parameter:
% degradation (O2 consumption)
Value:
ca. 92
Sampling time:
28 d
Details on results:
Initial test material concentration: 100 mg/L
- Theoretical oxygen demand (ThOD) = 1.16 mg O2/mg
- % biodegradation on Day 4: > 10 %
- % biodegradation on Days 5: > 60 %
- % biodegradation on Days 28 = 92 %
Results with reference substance:
- Theoretical oxygen demand (ThOD) = 1.67 mg O2/mg
- % biodegradation on Day 14 = 84 %
- % biodegradation on Days 28 = 90 %

Table 5.2.1/2: Biodegradation in the Test Flasks

Time (days)

Percentage Biodegradation1

Test item

Procedure control

Toxicity control

Replicate No.

Replicate No.

Replicate No.

1

2

1

2

1

0

0

0

0

0

0

1

0

0

4

7

0

2

6

-2*

44

48

24

3

7

3

62

65

32

4

60

56

67

69

48

5

72

71

69

71

51

6

75

77

73

74

54

7

80

81

75

77

58

8

83

83

77

78

62

9

84

85

78

80

66

10

88

88

80

82

72

11

88

90

81

84

78

12

88

90

82

85

80

13

88

90

83

85

82

14

88

90

83

86

84

15

89

91

84

87

86

16

89

91

84

87

87

17

--

--

--

--

--

18

--

--

--

--

--

19

91

92

87

89

90

20

90

93

87

90

90

21

91

92

86

89

90

22

91

92

87

90

91

23

91

92

87

90

91

24

91

92

87

90

92

25

91

92

87

90

92

26

91

93

87

90

92

27

92

92

88

91

92

28

91

92

88

91

92

Mean (Day 28)

92

90

Not applicable

1 Corrected for the mean oxygen uptake of the inoculum controls (see Section 3.4)

-- Not determined

* Negative value due to higher oxygen consumption in the inoculum controls than in the test flasks with test item.

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Under the test conditions, Zinc Dimethacrylate was considered as readily biodegradable.
Executive summary:

In a ready biodegradation study performed according to OECD Guideline 301 F and GLP, Zinc Dimethacrylate (CAS 13189-00-9; EC: 236-144-8) was tested at a concentration of 100 mg/L and the inoculum was activated sewage sludge, domestic. The degradation of the test material was assessed by the determination of the oxygen consumption. The test treatments, inoculum blank and procedure control were measured in duplicates and one vessel was used for toxicity control. At 100 mg/L test concentration, greater than 10 % degradation was reached by Day 4 and greater than 60 % biodegradation was reached by Day 5. Hence, the test material met the 10-day window requirement for ready biodegradability. On Day 28, the biodegradation was 92 %. The reference material (sodium benzoate) reached greater than 60 % biodegradation within 3 days. The biodegradation in the toxicity control was 84 % within 14 days and had no toxic effect on the micro-organisms. Hence, it met the validity criteria for reference material and toxicity control. Under the test conditions, Zinc Dimethacrylate was considered as readily biodegradable (Eisner, 2013).

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion