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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: Well documented study according to international accepted guideline and GLP compliant.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: crystalline
Details on test material:
Test item: 4-Aminobutyric acid
CAS number: 56-12-2
Batch number BCBN4740V
Physical state: Solid, crystalline powder
Colour: White
Storage: at 15-30 °C

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, non-adapted
Details on inoculum:
Type of inoculum: aerobic mixed bacterial culture
Source: Municipal wastewater treatment plant, Esztergom-Kertváros
Duration of test (contact time):
28 d
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
PREPARATION OF INOCULUM TEST CULTURE
Before the test 300 ml stock culture was filtered through a filter with 0.2 mm pore size to remove the bigger insoluble particles and then the dry substance content of the filtrate was determined. The measured value was 0.78 g/L. As the dry substance was less than 1 g/l, the filtrate was used as inoculum culture directly.

PREPARATION OF REFERENCE SOLUTION
For the reference solution 320.12 mg sodium acetate was diluted in 100 ml mineral medium.

PREPARATION OF TEST VESSELS
Following test vessels were prepared and analysed for the study:
- Test item (in two replicates)
- Blank control (in two replicates)
- Reference solution (positive control)
- Reference and test item solution (toxicity control)
- Sterilized solution of test item (abiotic control)
Reference substance
Reference substance:
acetic acid, sodium salt

Results and discussion

% Degradation
Parameter:
% degradation (O2 consumption)
Value:
80
Sampling time:
28 d
Remarks on result:
other: mean of two replicates
Details on results:
The biodegradability of the test item on day 12th was 74%. The abiotic degradation of the test item was 1% at the end of the test.

BOD5 / COD results

Results with reference substance:
Reference solution (positive control): 85%
Reference and test item solution (toxicity control): 68%
Sterilized solution of test item (abiotic control): 1%

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
According to OECD guideline the test item should be classified as readily biodegradable if the percentage biodegradation reaches 60% of theoretical oxygen demand within 28 day period in a 10-day window. Based on ready biodegradability testing results the 4-Aminobutyric acid is readily biodegradable.