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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: inherent biodegradability
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
08 Jan - 05 Feb 1990
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
documentation insufficient for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1990
Report Date:
1990

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
Concentration: 1 g/L dry matter
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L
Based on:
DOC
Parameter followed for biodegradation estimationopen allclose all
Parameter followed for biodegradation estimation:
DOC removal
Parameter followed for biodegradation estimation:
other: discolouration
Details on study design:
Blank control performed

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (DOC removal)
Value:
27
Sampling time:
28 d
Parameter:
other: % degradation (based on discolouration)
Value:
53
Sampling time:
28 d

BOD5 / COD results

BOD5 / COD
Parameter:
COD
Value:
1 880 mg O2/g test mat.
Remarks on result:
other: 1 g/L
Remarks:
Method: DIN H41

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Interpretation of results:
not inherently biodegradable
Conclusions:
The substance showed a maximum biodegradation rate of 27% (based on DOC removal). The substance is not considered to be inherently biodegradable. Discolouration is not considered a suitable method to determine biodegradation, especially since the yellowish colouration of the test medium cannot be clearly related to the test item when activated sludge is added.