Ethanone, 2-chloro-1-(1-chlorocyclopropyl)-

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

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:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

not applicable

Qualifier:

according to guideline

Guideline:

EU Method C.4-E (Determination of the "Ready" Biodegradability - Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Type: mixed population of aquatic microorganisms
- Source of sewage effluent: secondary effluent of a domestic sewage treatment plant (Odenthal)
- Date of collection: 2001-08-24
- Preconditioning: seperation of coarse particles by filtratio, aeration of mineral medium plus inoculum (filtrate) for 4 days
- Effluent concentration in reaction mixture: 5 mL/L

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Pretreatment of the test substance:
- The test substance was weighed out on aluminium foil. This substance inclusive the aluminium foil was added to the test vessels.
- Initial concentration of the test substance 2.0 mg test substance/L

Reference compound:
- Initial concentration of the reference compound : 2.9 test substance/L

Exposure conditions:
- Incubation time: 28 days
- Incubation temperature: 20 ± 1 °C

Reference substance:

benzoic acid, sodium salt

Remarks:

purity 99 %

Preliminary study:

The initial concentration of the test substance has been reduced in the main test, because the test substance showed a toxic effect against bacteria in the preliminary test.

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

14 d

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

21 d

Results with reference substance:

68 % degradation after 7 d
76 % degradation after 14 d
81 % degradation after 21 d
81 % degradation after 28 d

Toxicity Control:
No toxicity of the test substance was observed.

Validity criteria fulfilled:

yes

Remarks:

for details see 'overall remarks'

Interpretation of results:

not readily biodegradable

Conclusions:

The substance showed 0 % degradation after 28 days. Therefore the substance has to be classified as "Not Readily Biodegradable".

Executive summary:

The study was conducted in accordance with the Council Directive 92/69/EEC Method C.4-E: Closed Bottle Test. This test method is in all essential parts identical with OECD Guideline 301 D. The test substance in a mineral medium was inoculated with secondary effluent and incubated for 28 d under aerobic conditions in completely full, closed bottles. During this period the biodegradation is followed by analysis of dissolved oxygen. The amount of oxygen taken up by the test chemical, corrected for uptake by the blank inoculum run in parallel, is expressed as a percentage of theoretical oxygen demand (ThOD) or chemical oxygen demand (COD). The substance showed 0 % degradation after 28 days. Therefore the substance has to be classified as "Not Readily Biodegradable". The reference compound showed 76 % degradation after 14 days.

Description of key information

The study was conducted in accordance with the Council Directive 92/69/EEC Method C.4-E: Closed Bottle Test. This test method is in all essential parts identical with OECD Guideline 301 D. The test substance in a mineral medium was inoculated with secondary effluent and incubated for 28 d under aerobic conditions in completely full, closed bottles. During this period the biodegradation is followed by analysis of dissolved oxygen. The amount of oxygen taken up by the test chemical, corrected for uptake by the blankinoculum run in parallel, is expressed as a percentage of theoretical oxygen demand (ThOD) or chemical oxygen demand (COD). The substance showed 0 % degradation after 28 days. Therefore the substance has to be classified as "Not Readily Biodegradable".

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

The reference compound showed 76 % degradation after 14 days.