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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:
01.06-29.06. 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study and data are well documented and scientifically acceptable.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report date:
1992

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
ISO DIS 9408 (Ultimate Aerobic Biodegradability - Method by Determining the Oxygen Demand in a Closed Respirometer)
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, adapted
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
100 mg/L

Results and discussion

% Degradation
Parameter:
% degradation (DOC removal)
Value:
2
Sampling time:
28 d

BOD5 / COD results

BOD5 / COD
Parameter:
BOD5
Value:
4

Any other information on results incl. tables

Mean value of duplicates for DOC, mg/L

Product name

Test conc.

BOD28

DOC0

DOC28

DOC-rem.

Iodixanol

100 mg/l

4

25.0

24.4

2 %

Applicant's summary and conclusion

Interpretation of results:
not inherently biodegradable
Conclusions:
No significant DOC removal was obtained in the course of the test period. A low, but significant BOD was recorded.The product will be classified as not readily biodegradable according to the OECD criteria which require a DOC removal of 70% in 28 days for classification as "readily degradable".