(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17-one

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jul - Aug 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline under GLP

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17-one

EC Number:

228-351-7

EC Name:

(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17-one

Cas Number:

6236-40-4

Molecular formula:

C20H28O2

IUPAC Name:

(3aS,3bR,9bS,11aS)-11a-ethyl-7-methoxy-1H,2H,3H,3aH,3bH,4H,5H,6H,9H,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-one

Details on test material:

- Name of test material (as cited in study report): Ethyldienon
- Analytical purity: 89.1%
- Lot/batch No.: 21400404

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

10 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

20 mg/L

Based on:

test mat.

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

0 - 2

Sampling time:

28 d

Details on results:

The reference compound sodium acetate was degraded to 100%, the test compound
Ethyldienon was degraded to 2%. The variation in the degradation is within the accuracy of the method.

Any other information on results incl. tables

Table 1: Biological degradation (cumulative) in percent

		Day of sampling
Test compound	Nominal concentration	3	4	7	11	16	21	25	29
Sodium
acetate	20 mg/L	18	31	54	80	96	102	105	105
ZK 28519	10 mg/L	1	1	1	2	0	0	1	0
ZK 28519	20 mg/L	0	0	0	0	0	0	1	2

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

In accordance with the OECD guideline, the test product Ethydienon is not readily biodegradable under the conditions of the test.

Executive summary:

The purpose of this study was to determine the ready biodegradability of the product Ethyldienon (ZK 28519). The study was conducted in agreement with the following test guideline: OECD guidelinefor testing of chemieals: Ready biodegradability: Modified Sturm test, No. 301 B, adopted May 1981.

The test substance was incubated in aqueous solution including nutrients with microorganisms fram a municipal sewage treatment plant for 28 days (start of treatment = day 1). The nutrient solutions were made up of phosphates, ammonium sulphate, magnesium sulphate, iron chloride, ammonium chloride and calcium chloride, and added to the test solution. Additionally, a reference substance (sodium acetate) was tested according to the same procedure, in order to verify the viability and activity of the degrading microorganisms. The test substance was incubated in two concentrations (10 mg/L and 20 mg/L suspension) and the reference substance in a concentration of 20 mg/L. Furthermore, one additional vessel without any test or reference substance was used as blank (control). The biological degradation of the test and reference substances was evaluated by measurement of the CO2 produced during the test period. CO2-production was determined on days 3, 4, 7, 11, 16, 21, 25, and 29 and calculated as the percentage of total CO2 that the test material could theoretically have produced, based on carbon content. The blank CO2 - production was subtracted for correction.

The test compound ZK Ethyldienon was degraded to 2%.