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Environmental fate & pathways

Biodegradation in water: screening tests

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Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study performed according to current OECD-Guideline, well documentde but without GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2004
Report date:
2004

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
GLP compliance:
no

Test material

Constituent 1
Reference substance name:
Decanoyloxybenzoic acid
IUPAC Name:
Decanoyloxybenzoic acid
Constituent 2
Reference substance name:
SEEAUS 035
IUPAC Name:
SEEAUS 035

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
Activated sludge from sewage treatment plant FrankfurtNiederrad
Duration of test (contact time):
28 d
Initial test substance concentrationopen allclose all
Initial conc.:
16.6 mg/L
Based on:
test mat.
Initial conc.:
16.8 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution
Reference substance
Reference substance:
benzoic acid, sodium salt

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
80
Sampling time:
28 d
Details on results:
The test substance Decanoyloxybenzoic acid in the concentration of 24 mg/I reached a degree of degradation of 80 % after 28 days. The level of 10 % degradation (begin of biodegradation) was reached after 1 day. The 60 % level was passed after 7 days. The pass level for ready biodegradability, i. e. ~ 60 % theoretical'C02 production within 10 days after the degree ofdegradation has reached 10 % (l0 d window), was reached. The test substance is readily biodegradable.
In order to check the validity ofthe test sodium benzoate in a concentration of 20 mg/l was used as reference substance. The pass level of60 % degradation within '14 days was reached. In a toxicity test, containing both the test substance and the reference substance, the degradation reached 82 %. The test substance can be assumed to be not inhibitory

Any other information on results incl. tables

Degree of degradation of the test substance (S1: 24.3 mg/l, S2: 23.9 mg/l)

 

                                       Degr. [%]

Study day (d)              Sl               S2

2                               22              21

5                               45              43

7                               62              59

9                              71              69

12                            76              76

16                            78              78

21                             79              80

28                            79              81

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
The test substance Decanoyloxybenzoic acid in the concentration of 24 mg/I reached a degree of degradation of 80 % after 28 days. The level of 10 % degradation (begin of biodegradation) was reached after 1 day. The 60 % level was passed after 7 days. The test substance is readily biodegradable.
Executive summary:

The ready biodegradability ofthe test substance Decanoyloxybenzoic acid was tested in the CO2 Evolution Test with non-adapted inoculum over a period of 28 days according to DECD Guideline for Testing of Chemicals 301 B. The test substance Decanoyloxybenzoic acid in the concentration of 24 mg/I reached a degree of degradation of 80 % after 28 days. The level of 10 % degradation (begin of biodegradation) was reached after 1 day. The 60 % level was passed after 7 days. The pass level for ready biodegradability, i. e. ~ 60 % theoretical'C02 production within 10 days after the degree ofdegradation has reached 10 % (l0 d window), was reached. The test substance is readily biodegradable.

In order to check the validity ofthe test sodium benzoate in a concentration of 20 mg/l was used as reference substance. The pass level of 60 % degradation within '14 days was reached. In a toxicity test, containing both the test substance and the reference substance, the degradation reached 82 %. The test substance can be assumed to be not inhibitory. The validity criteria according to the guideline were fulfilled in the test.