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

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:

Nov - Dec 1995

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:

1996

Report date:

1996

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-17β-ol

EC Number:

213-860-9

EC Name:

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

Cas Number:

1038-28-4

Molecular formula:

C20H30O2

IUPAC Name:

11a-ethyl-7-methoxy-1H,2H,3H,3aH,3bH,4H,5H,6H,9H,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-ol

Details on test material:

- Name of test material (as cited in study report): Ethyldienol
- Analytical purity: 80.9 - 93.9%
- Lot/batch No.: mixed batches

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Duration of test (contact time):

27 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

DOC

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

28 d

Details on results:

On the basis of the CO2 production in the toxicity control, the reference compound sodium
acetate was degraded to 72% on day 7 (~ 6 days of incubation) and was further degraded up
to 96% on day 29 (~ 27 days of incubation).

Any other information on results incl. tables

Table 1: Biological degradation (cumulative) in percent (corrected tor blank C02 production)

Test compound	Nominal concentration	Day of sampling
	of carbon	4	7	10	14	18	23	28
ZK 47569	10 mg/L	0	0	1	0	0	0	0
Sodium acetate	10 mg/L	-30	-54	-64	-78	-86	-90	-96
(reference)
ZK 47569 + sodium	10 mg/L +	15	27	33	38	43	45	48
acetate (toxicity control)	10 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

In accordance with the OECD guideline, the test compound ZK 47569 is not readily
biodegradable under the conditions of the test and it was not toxic to the microbes of activated
sludge.

Executive summary:

The purpose of this study was to determine the ready biodegradability of Ethyldienol (ZK 47569). The study

was conducted in agreement with the following test guideline: OECD guideline tor testing of chemicals, Ready biodegradability: C02-evolution test, no. 301B.

The test substance was incubated in an aqueous solution including nutrients with microorganisms trom a municipal sewage treatment plant for 27 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.

The test substance was incubated in a concentration of 10 mg carbon/L in triplicate.

Additionally, a reference substance (sodium acetate) was tested according to the same

procedure, in order to verity the viability and activity of the degrading microorganisms.

Furthermore, a blank contral was tested in triplicate without any test or reference substance.

One further set was incubated with sodium acetate as 10 mg, carbon/L (reference substance)

plus test substance as 10 mg carbon/L representing toxicity control.

The biological degradation of the test and reference substances was evaluated by

measurement of the carbon dioxide (C02) produced during the test period. CO2 production

was determined on days 4, 7, 10, 14, 18, 23 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 was practically not degraded.