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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The data source is the competent authority. Although details on test method and results are not completely described, the results are sufficient to estimate the biodegradation properties of the substance.
Cross-reference
Reason / purpose for cross-reference:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
Deviations:
yes
Remarks:
7 day-test, no data on water composition and inoculum.
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
1,1,2-trichloro-1,2-difluoroethane
EC Number:
940-543-9
Cas Number:
354-15-4
Molecular formula:
C2HCl3F2
IUPAC Name:
1,1,2-trichloro-1,2-difluoroethane
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): R122
- Molecular formula: CHCIF–ССI2F

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
not specified
Duration of test (contact time):
7 d
Initial test substance concentrationopen allclose all
Initial conc.:
9.36 mg/L
Based on:
act. ingr.
Initial conc.:
18.72 mg/L
Based on:
act. ingr.
Initial conc.:
37.44 mg/L
Based on:
act. ingr.

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Sampling time:
7 d
Remarks on result:
other: No significant effect of tested concentrations of HCFC 122a on biochemical oxygen consumption was observed.

Any other information on results incl. tables

Biochemical oxygen consumption.

HCFC 122a concentration (mg/l)

Day 1

Day 3

Day 5

Day 7

mg/l O2

% in comparison with control

mg/l O2

% in comparison with control

mg/l O2

% in comparison with control

mg/l O2

% in comparison with control

Control

1.2

100

2.4

100

2.6

100

2.9

100

9.36

1.19

99

2.35

98

2.57

99

2.81

95

18.72

1.16

97

2.33

97

2.5

96

2.76

95

37.44

1.14

95

2.31

96

2.47

95

2.73

94

The comparison between the amount of dissolved oxygen in the control water and in the experimental samples showed no significant effect of tested concentrations of HCFC 122a on biochemical oxygen consumption. The authors assumed that HCFC 122a were practically inert in terms of influence on the dynamics of biochemical oxygen consumption.

It can be concluded that no degration occurred under test conditions.

Applicant's summary and conclusion

Validity criteria fulfilled:
not applicable
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
No significant effect of tested concentrations of HCFC 122a on biochemical oxygen consumption was observerd. It can be concluded that no degradation occurred under test conditions.
Executive summary:

The study was carried out to evaluate the influence of the substance on the dynamics of oxygen consumption in order to set the threshold concentrations and the approximate permissible levels in water. The test was conducted in accordance with the “Guidelines for the design and the scientific validation of the maximum allowable concentrations of harmful substances in water bodies” (1976).

HCFC 122a was added at three different concentrations to specially prepared water placed in bottles and the amount of oxygen consumption was analyzed on a period of 7 days. The biochemical oxygen consumption was determined on the 1st, 3rd, 5th, and 7th day.

The comparison between the amount of dissolved oxygen in the control water and in the experimental samples showed no significant effect of tested concentrations of HCFC 122a on biochemical oxygen consumption. The authors assumed that HCFC 122a were practically inert in terms of influence on the dynamics of biochemical oxygen consumption.

Basing on the results it can be concluded that no degration occurred under test conditions.