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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: inherent biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1988
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: according to Zahn-Wellens test (only test results reported)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method C.9 (Biodegradation: Zahn-Wellens Test)
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
3-methyl-1-p-tolyl-5-pyrazolone
EC Number:
201-708-4
EC Name:
3-methyl-1-p-tolyl-5-pyrazolone
Cas Number:
86-92-0
Molecular formula:
C11H12N2O
IUPAC Name:
5-methyl-2-(4-methylphenyl)-1,2-dihydro-3H-pyrazol-3-one

Study design

Oxygen conditions:
not specified
Inoculum or test system:
not specified
Details on inoculum:
no further detailed information reported about inoculum used for this Zahn Wellens test
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
394 other: mgC/L
Based on:
DOC
Initial conc.:
1 542 other: mgO2/L
Based on:
COD
Reference substance
Reference substance:
not specified

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
3 h
Parameter:
% degradation (DOC removal)
Value:
5
Sampling time:
5 d
Parameter:
% degradation (DOC removal)
Value:
0
Sampling time:
10 d
Parameter:
% degradation (DOC removal)
Value:
8
Sampling time:
15 d
Parameter:
% degradation (DOC removal)
Value:
30
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Interpretation of results:
other: hardly to moderately biodegradable
Conclusions:
The tested substance is hardly to moderately biodegradable.
Executive summary:

A biodegradation range of 30 -70% is possible since after 15d of adaption a clear biodegradation started; biodegradation could possibly be higher if the test was based on an adapted inoculum