Acetoacetamide

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: screening test, other

Remarks:

Test wa performed acc to DIN 38412 part 25, similar to OECD 302 B; no GLP

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 May 1989 - 14 June 1989

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Deviations:

yes

Remarks:

origins of the sludge and test substance concentration

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.9 (Biodegradation: Zahn-Wellens Test)

Deviations:

yes

Remarks:

already mentioned

Principles of method if other than guideline:

DIN 38 412 Part 25 (1984). This method is corresponding with small differences to the Guideline OECD 302B and EU Test method C.9.

GLP compliance:

no

Remarks:

newly generated from 1989 report

Specific details on test material used for the study:

Test substance dissolved in approx. 30% in aqueous solution

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, industrial, non-adapted

Details on inoculum:

Mixture of activated sludge from the sewage treatment plant from one industrial site and activated sludge from the other industrial site.

Duration of test (contact time):

28 d

Initial conc.:

357.9 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

Stock solution:
5 g 30% acetoacetamide solution were mixed with 1800 ml de-ionized water, the pH adjusted from 6.9 to 7.1. This batch was stirred over a period of 24 hours at 22°C. The resulting clear solution was filled up with de-ionized water to a final volume of 2000 ml and used as stock solution.
Inoculum:
Washing the sediment from the activated sludge two times by centrifuging and resuspending in mineral medium. 12 g/L (=1240 mg dry mass/L) was used for the batch.12 g/L of wet centrifuged sludge was used as inoculum.
241 ml/L stock solution was added. Test item concentration: 357.9 mg/L

Reference substance:

diethylene glycol

Remarks:

271.6 mg DOC/L

Test performance:

During the first 7 days of the test the DOC exhaustion achieved >70% of the carbon content of the added test substance, but during the following 7 days the rate of degradation stayed at the plateau in the range of 70% to 72%.

Parameter:

% degradation (DOC removal)

Value:

32

Sampling time:

1 d

Parameter:

% degradation (DOC removal)

Value:

70

Sampling time:

9 d

Parameter:

% degradation (DOC removal)

Value:

68

Sampling time:

21 d

Key result

Parameter:

% degradation (DOC removal)

Value:

64

Sampling time:

28 d

Remarks on result:

other: inherently biodegradable

Details on results:

The results were confirmed by additionally conducted COD control analyses. The analysis of the COD before adding the inoculum resulted in a start value of 510 mg/L COD from the test substance in the test batch. The final COD (28 days, test minus blank) was 160 mg/L, corresponding to 69% elimination.

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

Acetoacetamide (30% solution) is inherently biodegradable under the conditions of the zahn-Wellens Test.

Executive summary:

A 30% aequous solution of acetoacetamide was tested for inherent biodegradation in the Zahn-Wellens-test by measuring the DOC disappearance. During the first 7 days of the test the DOC exhaustion achieved > 70% of the carbon content of the added test substance, but the following day the rate of degradation staye at the plateau in the range 70 - 72%. The results were confirmed by additionally conducted COD control analyzes. COD at the start was 510 mg/L and 160 mg/L after 28 days, corresponding to an elimination of about 69%.

Acetoacetamide (30% solution) is inherently biodegradable under the conditions of the zahn-Wellens Test.

Description of key information

Acetoacetamide (30% solution) is inherently biodegradable under the conditions of the zahn-Wellens Test.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater