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)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2009
Report Date:
2009

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
Details on test material:
939-76

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
ca. 0.8
Sampling time:
28 d

Applicant's summary and conclusion

Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Under the test conditions the percentage biodegradation of AA-AAOA (Anthranilic Acid-AAOA Coupling) reached a mean of 0.8 % after 28 days based on its ThODNO3. The test item can therefore be considered to be not ready biodegradable. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThODNO3.
Executive summary:

The test item AA-AAOA (Anthranilic Acid-AAOA Coupling) was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item Sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control. The test system was a microbial inoculum of good quality, collected from the sewage plant for domestic sewage. The sludge was washed by centrifugation filtered through cotton wool and aerated until use. Based on the determined dry weight content, the washed sludge suspension contained 4 g dry material per litre. Under the test conditions the percentage biodegradation of AA-AAOA (Anthranilic Acid-AAOA Coupling) reached a mean of 0.8 % after 28 days based on its ThODNO3. The test item can therefore be considered to be not ready biodegradable. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThODNO3. The reference item Sodium benzoate was sufficiently degraded to a mean of 96.7 % after 14 days, and to a mean of 91.7 % after 28 days of incubation, based on ThODNH4, thus confirming the suitability of the used activated sludge inoculum. In the toxicity control containing both, the test item and the reference item Sodium benzoate, a mean of 47.9 % biodegradation was noted within 14 days and 45.0 % 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 2.8 mg/L on the activated sludge microorganisms because degradation was >25 % within 14 days.