Registration Dossier

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
other information
Study period:
Feb - Mar 1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1999
Report Date:
1999

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): ZK 34517 (3ß,5-Dihydroxy-6ß, 7ß; 15ß, 16ß-dimethylene-5ß-androstan-17 -one)
- Analytical purity: (1) 96.1, (2) 97.7, (3) 97.5, (4) 96.6, (5) 96.5, (6) 97.9, (7) 97.9%
- Lot/batch No.: Mixed batches: (1) 27002001, (2) 27002002, (3) 27002003, (4) 27002004, (5) 27002005, (6) 27002006, (7) 27002007




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 conc.:
10 mg/L
Based on:
test mat.

Results and discussion

% Degradation
Parameter:
% degradation (CO2 evolution)
Value:
3
Sampling time:
30 d
Details on results:
The test compound Dimethylenketon was degraded to 3% on day 30 (28 days of incubation).
The reference compound sodium acetate was degraded to 71% on day 9 (8 days of incubation) and up to 100% on day 28.
In the toxicity control, the reference compound (sodium acetate) plus the test compound was degraded to 52% on day 30 (28 days of incubation).

Any other information on results incl. tables

The CO2 produced by the blank control (20.1 mg/L) was within the limit set by the OECD guideline (40 mg/L). The criteria set by the OECD guideline require that the reference substance is degraded to 60% or more within 14 days after start of incubation. The reference substance sodium acetate was degraded to 71 % within 8 days of incubation. Hence, the yalidity criteria of the OECD guideline were fulfilled, i.e. the inoculum was viable and active.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Interpretation of results:
inherently biodegradable
Conclusions:
In accordance with the OECD guideline, the test compound Dimethylenketon 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 Dimethylenketon (ZK 34517), which is an

intermediate of the synthesis of drospirenone (gestagen). The study was conducted in agreement with the OECD test guideline no.301 B and the EC guideline. The test substance Dimethylenketon was incubated in an aqueous solution including nutrients with

microorganisms from a municipal sewage treatment plant for 28 days (start of treatment =day 1).

The test substance was incubated in a concentration of 10 mg carbon/L in triplicate. The biological degradation of the test and reference substances was evaluated by measurement of the carbon dioxide (C02) produced during the test period.

The test compound Dimethylenketon was degraded to 3% on day 30 (28 days of incubation). In accordance with the OECD guideline, the test compound ZK 34517 is not readily biodegradable under the conditions of the test and it was not toxic to the microbes of activated sludge.