Registration Dossier

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
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report):1,3-Dimethylurea
- Lot/batch No.: 00001075-0
- Analytical purity: 98.6 %
Water-solubility: 1000 g/l

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): activated sludge taken from a laboratory wastewater treatment plant fed with municipal sewage; not adapted.
- Concentration of sludge: 30 mg/l
Duration of test (contact time):
21 d
Initial test substance concentrationopen allclose all
Initial conc.:
20 mg/L
Based on:
DOC
Initial conc.:
50 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
DOC removal
Reference substance
Reference substance:
aniline

Results and discussion

% Degradation
Parameter:
% degradation (DOC removal)
Value:
90 - 100
Sampling time:
21 d
Details on results:
Duration of the adaptation phase: 6 days.
Duration of the degradation phase: 11 days.
Degradation of the test substance at the end of the 10-day
Window: 90-100 % DOC removal.
Degradation of the test substance at the end of the test: 90-100 % DOC removal.

Physico-chemical (abiotic) elimination of the test
Substance: < 10 % at the end of the test.
Elimination of the test substance by adsorption: < 10 % after 5 days.

Degradation of the reference substance after 14 days: 90 -100 % DOC removal.
Degradation in the inhibition control after 14 days: 90 - 100 % DOC removal.

The validity criteria as laid down in OECD TG 301 were fulfilled.

Kinetic of test substance (in %):
0 after 1 day(s)
0 after 3 day(s)
= 0 -6 after 5 day(s)
= 23 - 25 after 7 day(s)
= 93 - 94 after 10 day(s)
Kinetic of control substance (in %):
= 9 after 1 day(s)
= 94 after 3 day(s)
Degradation products: not measured

Applicant's summary and conclusion

Interpretation of results:
readily biodegradable