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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1992
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP laboratory study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: OECD DOC-Die away test (EG-Richtlinie 92/69 EWG, Tiel II, C.4-A)
Principles of method if other than guideline:
Equivalent to OECD 301A
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
C10-13-sec alkyl derivative, Benzosulfonic acid (CAS #85536-14-7); purity 97.3%

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
11.3 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Details on study design:
A measured volume of inoculated mineral medium, containing a known concentration of the test substance (10-40 mg DOC/l) as the nominal sole source of organic carbon, is aerated in the dark or diffuse light at 22 ± 2°C. Degradation is followed by DOC analysis at frequent intervals over a 28-day period. The degree of biodegradation is calculated by expressing the concentration of DOC removed (corrected for that in the blank inoculum control) as a percentage of the concentration initially present.
Reference substance
Reference substance:
benzoic acid, sodium salt
Remarks:
99.5% purity

Results and discussion

% Degradation
Key result
Parameter:
% degradation (DOC removal)
Value:
94
Sampling time:
28 d
Details on results:
readily biodegradable

BOD5 / COD results

Results with reference substance:
Biodegradation with the reference substance, sodium benzoate, at 11.8 mg DOC/L resulted in 96% degradation in 28 days.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Executive summary:

The substance was tested in a 28 -day DOC-die away test and found to be degraded by 94% in 28

days. The substance is readily biodegradable.