Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Currently viewing:

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2011
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
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, domestic (adaptation not specified)
Duration of test (contact time):
28 d

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
64.7
Sampling time:
28 d
Details on results:
The final mean percent biodegradation for squalane was 64.7%. In addition the pass level must be reached within 10 days of achieving 10% TCO2.
Since squalane did achieve the pass level of 60% TCO2, though no within 10 days of achieving 10% TCO2, it may be considered inherently biodegradable.

Any other information on results incl. tables

Results :

Days Squalane
Cumulative % TCO2
Flask 1 Flask 2
3 -2.1 -2.1
6 -3.2 -3.2
9 -4.7 -4
13 8.4 12
16 17.1 21.5
20 29.7 32.4
23 41.3 42.8
27 54.1 58.2
29 62.1 67.3

Applicant's summary and conclusion

Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
Since squalane did achieve the pass level of 60% TCO2 after 28 days of incubation, though not within 10 days achieving 10% TCO2, it may be considered inherently biodegradable.
Executive summary:

The ready biodegradation of the squalane was determined by the carbon dioxide evolution test method (OCDE guideline 301B). Tests of ready biodegradability are stringent tests that provide limited oppotunity for acclimation and biodegradation to occur. In the CO2 test, inoculated mineral medium was dosed with a known amount of test substance as the nominal sole source of organic carbon and aerated with CO2 -free air. The CO2 produced from the mineralization of organic carbon within the test chambers was displaced by the flow of CO2 -free air and trapped as K2CO3 in KOH trapping solution. The amount of CO2 produced by the test substance is expressed as a percentage of the theoretical amount of CO2 that could have been produced if complete biodegradation of the substance occured. The test contained a blank control, three reference groups and one treatment group. Each group contained two replicate test chambers. The blank control was used to meseare the background CO2 production of the inoculum and was dosed with a carbon source. The reference chambers were dosed with either canola oil, Synfluid or Ultra Low Sulfur Diesel at a concentration of 10 mg C/L. The treatment group test chambers were used to evaluate the test substance at concentration of approximately 10 mg C/L. The results indicated that the activated sludge inoculum was active, degrading the canola oil reference 99.9%. The average cumulative percent biodegradation for squalane was 64.7%. However, squalane may be considered inherently biodegradable because it reached 60% of TCO2, though not within a 10 -days window of reaching 10% TCO2.