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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:
key study
Study period:
July 16, 2013 - December 31, 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)
Version / remarks:
2008
Deviations:
no
Qualifier:
according to
Guideline:
EPA OPPTS 835.3100 (Aerobic Aquatic Biodegradation)
Version / remarks:
1998
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic (adaptation not specified)
Details on inoculum:
- Source of inoculum/activated sludge: Nanjing Chengdong Sewage Treatment Plant, treating predominantly domestic sewage
- Preparation of inoculum for exposure: Sludge was washed and centrifuged at 4°C. Washing procedure repeated 3 times.
- Concentration of sludge: 4 g/L dw
- Initial cell/biomass concentration: 30 mg(L
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
9 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
TEST CONDITIONS
- Composition of medium: based salt medium
- Test temperature: 22 +- 1°C
- pH: 7.96 - 8.21

TEST SYSTEM
- Culturing apparatus: glass bottles 500 mL
- Number of culture flasks/concentration: 2

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 flasks
- Toxicity control: 1 flask
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradation
Key result
Parameter:
% degradation (O2 consumption)
Value:
< 1
Sampling time:
28 d

BOD5 / COD results

Results with reference substance:
76.0% in 14 days

Any other information on results incl. tables

Inoculum blank: O2 uptake 19.9 mg/L in 28 d

Toxicity control: 37.3% in 14 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
The ready biodegradabilityh of the test item was determined in a study according to OECD 301F (Manometric Respirometry Test). The biodegradation was determined to be <1% after 28 d. Biodegradation of the reference substance and the results of the controls were within the validity criteria. Therefore, the test item has to be considered as not readily biodegradable under the conditions of this test.