Androst-4-ene-3,17-dione

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

Study period:

Sep to Oct 1994

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

10 - 20 mg/L

Based on:

test mat.

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

60

Sampling time:

9 d

Parameter:

% degradation (CO2 evolution)

Value:

>= 79 - <= 92

Sampling time:

29 d

Remarks on result:

other: 79 % at 20 mg/l; 92 % at 10 mg/l

Results with reference substance:

The reference substance passed 60% degradation between day 7 and day 9

Validity criteria for the measurement of the biodegradation according to OECD 301:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
In order to check the procedure, reference compounds which meet the criteria for ready biodegradability are tested by setting up an appropriate vessel in parallel as part of normal test runs. Suitable compounds are aniline (freshly distilled), sodium acetate and sodium benzoate.	Acetic acid, sodium salt was used as a reference compound.	Yes
A test is considered valid if the difference of extremes of replicate values of the removal of the test chemical at the plateau, at the end of the test or at the end of the 10-d window, as appropriate, is less than 20% and if the percentage degradation of the reference compound has reached the pass levels by day 14.	% degradation of the test substance at the end of the test (29 d) is 92%	Yes
If in a toxicity test, containing both the test substance and a reference compound, less than 35% degradation (based on total DOC) or less than 25% (based on total ThOD or ThCO2) occurred within 14 days, the test substance can be assumed to be inhibitory. The test series should be repeated, using a lower concentration of test substance (if this can be done without seriously impairing the accuracy of the DOC determination) and/or a higher concentration of inoculum, but not greater than 30 mg solids/L.	The used concentrations of the test substance did not show toxic effects to bacteria.	Yes

 

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

In the study on ready biodegradability a degradation rate of 79 % (20 mg/L) and 92 % (10 mg/L) were determined within 28 days for Androst-4-ene-3,17-dione .

Executive summary:

The study was conducted in accordance with the OECD Guideline 301 B to assess the ready biodegradability. The test substance was incubated at two concentrations (10 and 20 mg/L) for 28 days. Additionally, a reference substance (sodium acetate) was tested according to the same procedure at a concentration of 20 mg/L. The biological degradation was evaluated by the measurement of the CO₂ production. CO₂ was determined on days 3, 4, 7, 9, 16, 23 and 29 and the degradation was calculated as the percentage of the theoretical CO₂ production based on the structural formula (carbon content). The blank CO₂ procution was subtracted for correction. The test compound was degraded to 79 % (20 mg/L) and 92 % (10 mg/L) and therefore has to be classified as "Readily Biodegradable". This study is classified as acceptable and satisfies the guideline requirements for the Ready Biodegradability test.

Description of key information

In the study on ready biodegradability a degradation rate of 79 % (20 mg/L) and 92 % (10 mg/L) were determined within 29 days for Androst-4-ene-3,17-dione.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Androst-4-ene-3,17-dione showed a degradation rate of 79 % (20 mg/L) and 92 % (10 mg/L) within 29 days and therefore has to be classified as "readily biodegradable".