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: GLP study according to Guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2002

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
1992
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Version / remarks:
1992
Deviations:
no
GLP compliance:
yes (incl. certificate)
Remarks:
Ministerium für Umwelt, Raumordnung und Landwirtschaft des Landes Nordrhein-Westfalen

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
- Water solubility (under test conditions): test item reacts with water



OTHER PROPERTIES (if relevant for this endpoint)
- Adsorption characteristics:
- Toxicity to microorganisms:
- Other:

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Marl-Ost municipal sewage treatment plant
- Storage conditions: aerated with moist air in the dark
- Storage length: six days with mineral medium
- Preparation of inoculum for exposure: 2x5990 ml mineral medium were inoculated with 10 ml of inoculum
- Pretreatment:
- Concentration of sludge: 4.7 mg/l suspended solids, 2.1818 g/l dry matter
- Initial cell/biomass concentration: 86 x 10^4 CFU/ml
- Water filtered: no
Duration of test (contact time):
ca. 28 d
Initial test substance concentration
Initial conc.:
ca. 37.7 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: mineral medium
- Solubilising agent (type and concentration if used): not used
- Test temperature: 21.4-22.7°C
- pH: 7.2 at the end of the test
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water: no
- Suspended solids concentration: no data
- Continuous darkness: yes



TEST SYSTEM
- Culturing apparatus:
- Number of culture flasks/concentration:
- Method used to create aerobic conditions:
- Method used to create anaerobic conditions:
- Measuring equipment:
- Test performed in closed vessels due to significant volatility of test substance:
- Test performed in open system:
- Details of trap for CO2 and volatile organics if used:
- Other:


SAMPLING
- Sampling frequency:
- Sampling method:
- Sterility check if applicable:
- Sample storage before analysis:
- Other:


CONTROL AND BLANK SYSTEM
- Inoculum blank:
- Abiotic sterile control:
- Toxicity control:
- Other:


STATISTICAL METHODS:
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

Preliminary study:
not performed
Test performance:
Test is considered as valid if
- the mean percentage degradation in the vessels containing the reference compound is >= 60% on the 14th day of incubation (here 90%)
- The mean amount of IC produced from the test blank controls at the end of the test is <= 15% of the organic carbon added initially as the test compound (here -2.0%)
% Degradationopen allclose all
Parameter:
% degradation (CO2 evolution)
Value:
1
Sampling time:
3 d
Parameter:
% degradation (CO2 evolution)
Value:
20
Sampling time:
7 d
Parameter:
% degradation (CO2 evolution)
Value:
18
Sampling time:
14 d
Parameter:
% degradation (CO2 evolution)
Value:
23
Sampling time:
23 d
Parameter:
% degradation (CO2 evolution)
Value:
25
Sampling time:
28 d

BOD5 / COD results

Results with reference substance:
71% degradation after 3 days
94% degradation after 28 days

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Test substance is considered not readily biodegradable under conditions tested