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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: guideline study and GLP

Data source

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

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Name: Kn 172
Batch no.: Kn-Gi 9328-182
Appearance: white powder
Molecular formula: C13H18N4 x 3HCl
Molecular weight: 339.69 g/mol
Purity: NMR: 96.2%, 0.8% EtOH, 1.4% water
Solubility: H2O: >1g/L; EtOH; acetone; CH3CN; DMSO: unknown
Expiry date: 10.06.2013
Storage: fridge 2-8°C, keep away from light and humidity, keep under Ar!

The test item Kn 172 was tested using a concentration of nominally 20 mg organic carbon/
L (corresponding to 42.3 mg Kn 1721L) in test medium following OECD 301B and EUMethod
C.4-C.

Study design

Oxygen conditions:
aerobic
Inoculum or test system:
activated sludge, domestic, non-adapted
Duration of test (contact time):
28 d
Initial test substance concentration
Initial conc.:
42.3 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation
Parameter followed for biodegradation estimation:
CO2 evolution

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
0
Sampling time:
28 d
Details on results:
For the test item Kn 172, no relevant degradation was observed.
For the positive control, degradation lay within the usual values.
lf degradation in the toxicity flask is below 25% after 14 days, the test item can be considered
as toxic towards the inoculum. As degradation in the toxicity flask was 29% after 14
days, the test item can be stated as "not toxic towards the inoculum in a concentration of
42.3 mglL". lt is stated, though, that the amount of positive control which was added to the
toxicity flask did not degrade completely, as the lC values in the toxicity flask lay below the
lC values in the positive controls. Therefore, it is believed that a slightly toxic effect might
have taken place. On the other hand, a reaction between test item and positive control
could have produced a substance with worse degradation potential than aniline.
The result of the test can be considered valid.

Any other information on results incl. tables

Reference Substance:

Aniline (Phenylamine. CoHsNH2. CAS-Nr. 62-53-3) was used as readily bio-degradable positive control. A stock solution containing 2.1 glL (nominal) in deionised water was prepared and its organic carbon content was measured with 1707 ppm, resulting in an organic carbon content of 81.2 %.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
under test conditions no biodegradation observed
Conclusions:
Kn 172 is not readily biodegradable following OECD 301B/EU C.4-C.
Executive summary:

Summary

Title of Study: Determination of the aerobic ready biodegradability of Kn 172 in the CO2 Evolution Test following OECD 301B resp.

EU C.4.C

Findings and Results: The test item Kn 172 was tested using a concentration of nominally 20 mg organic carbon/L (corresponding to 42.3 mg Kn 172/L) in test medium following OECD 301B and EUMethod C.4-C.

Aniline was chosen as positive control.

Activated sludge was used as inoculum (concentration in the test 25.1 mg dry matter/L).

The test was left running for 28 days.

All validity criteria were met. Degradation of the reference item was 63 % after seven days.

The following data were determined for the test item Kn 172:

10-day-window: not detected

degradation at the end of 10-day-window: none

degradation at the end of the test: none

pass level: 60% at the end of 10-d-window

Therefore, Kn 172 is not readily biodegradable following OECD 301B/EU C.4-C.