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Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Nov - Dec 1995
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP
Cross-referenceopen allclose all
Reason / purpose for cross-reference:
reference to same study
Reason / purpose for cross-reference:
reference to other study

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Principles of method if other than guideline:
Not relevant
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
EC Number:
EC Name:
Cas Number:
Molecular formula:
13-ethyl-3-methoxy-4,6,7,8,9,11,12,13,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-17-ol (non-preferred name)
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:
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:

Results and discussion

% Degradation
% degradation (CO2 evolution)
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
 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:
Interpretation of results:
under test conditions no biodegradation observed
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
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.