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:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Report Date:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, domestic (adaptation not specified)
Duration of test (contact time):
ca. 28 d
Initial test substance concentration
Initial conc.:
ca. 8.1 mg/L
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradation
Key result
Parameter:
% degradation (O2 consumption)
Value:
3.3
Sampling time:
28 d
Details on results:
Under the test conditions the percentage biodegradation of the Test Item reached a mean of 3.3 % after 28 days based on the COD of the test item.
According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD/COD. Therefore the test item is considered not readily biodegradable.

In the toxicity control containing both, the test item and the reference item Sodium benzoate, a mean of 34.1 % biodegradation was noted within 14 days and 32.0 % biodegradation after 28 days of incubation.

According to the test guidelines the test item can be assumed to be not inhibitory at the applied concentration level of 8.1 mg/L on the secondary effluent microorganisms because degradation was >25 % within 14 days.

BOD5 / COD results

Results with reference substance:
The reference item Sodium benzoate was sufficiently degraded to a mean of 76.7 % after 14 days, and to a mean of 81.7 % after 28 days of incubation, based on ThOD, thus confirming the suitability of the used inoculum.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
not readily biodegradable
Conclusions:
The test item was not considered to have significant inhibitory effects on the secondary effluent microorganisms.
Based on the results of this study, the test item is considered not readily biodegradable.