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
Study period:
2008-07-14 - 2008-08-21
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The GLP study was conducted according to an internationally accepted guideline. All study parameters are based on the specific guideline.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
other: liquid

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge (adaptation not specified)
Details on inoculum:
The inoculum contained a mixed population of microorganisms obtained from the secondary effluent of the wastewater treatment plant of Pardubice processing predominantly municipal sewage.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
3.46 mg/L
Based on:
COD
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradationopen allclose all
Parameter:
% degradation (O2 consumption)
Value:
2.9
Sampling time:
3 d
Parameter:
% degradation (O2 consumption)
Value:
12.7
Sampling time:
7 d
Parameter:
% degradation (O2 consumption)
Value:
16.3
Sampling time:
14 d
Parameter:
% degradation (O2 consumption)
Value:
21.3
Sampling time:
21 d
Parameter:
% degradation (O2 consumption)
Value:
38.3
Sampling time:
28 d

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
other: not ready biodegradable
Conclusions:
The test substance, Weikoform (Urea, reaction products with formaldehyde), is not ready biodegradable.
Executive summary:

The test substance, Weikoform (Urea, reaction products with formaldehyde), was tested for the ready biological degradability in Closed Bottle Test. Test performance The test was performed according to: Method C.4E - Closed Bottle Test, Directive 92/69/EEC. Published in O.J. L 383A, 1992. The results of biological degradation are related to experimentally determined COD values of test and reference substance at the beginning of the test. Owing to the limited solubility of test substance in mineral medium the dosing of dispersion into each bottle was implemented. Sodium benzoate was used as the reference substance. The dosage was carried out from the stock solution. COD of the test substance in medium at the beginning of the main test: 3.46 mg/L COD of reference substance in medium at the beginning of the main test: 3.47 mg/L. In parallel to the main test the toxicity test was performed. As the test substance contains nitrogen in the chemical composition, the oxidized nitrogen forms were determined and the correction for nitrification was carried out. The test was performed at temperature of 20±1°C with the pH values of solutions 7-8 at the beginning of the test.

A degradation of 38.3 % of the test substance, Weikoform (Urea, reaction producst with formaldehyde), was attained.