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:
from 1994-08-31 to 1994-09-29
Reliability:
1 (reliable without restriction)
Cross-reference
Reason / purpose:
reference to other study

Data source

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

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
no
Principles of method if other than guideline:
NA
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid: viscous
Details on test material:
NA
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
NA

Study design

Oxygen conditions:
anaerobic
Details on inoculum:
The source of the test organisms was activated sludge freshly obtained from a multicipal sewage treatement plant. The sludge was kept under conditions aeration until further treatment. The concentration of suspended solids was 3.8 g/L in the concentrated sludge. Before use, the sludge was allowed to settle for at least 30 minutes and the liquid decanted for use as inoculum at the amount of 10 mL/L of mineral medium.
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
26.8 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
NA
Reference substance
Reference substance:
other: sodium acetate

Results and discussion

Preliminary study:
NA
Test performance:
NA
% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
> 10 - 12
Sampling time:
28 d
Details on results:
The relative degradation values calculated from the measurements performed during the test period revealed no significant (> 10 %) degradation of the test item in bottle A, and very slight degradation (12%) in bottle B.

BOD5 / COD results

Results with reference substance:
The control substance was degraded 82 % in 14 days and the complete degradation was reached at the end of the test period.

Any other information on results incl. tables

No remarks

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
The test substance was not readily biodegradable.
Executive summary:

Under the conditions of activated sludge respiration test the test item was found to be not toxic to waste-water bacteria at 100 mg per litre. Therefore, the test item was assumed to be not inhibitory at the concentrations used in the modified Sturm test presently performed. The test item was not readily biodegradable under the conditions of the modified Sturm test presently performed.