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Diss Factsheets

Environmental fate & pathways

Biodegradation in water: screening tests

Administrative data

biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
other information
Study period:
Mar - Apr 1998
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD giudeline under GLP

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)
GLP compliance:

Test material

Constituent 1
Chemical structure
Reference substance name:
7 beta-Hydroxy-3 beta,15 alpha-dipivaloyloxy-5-androsten-17-one
EC Number:
Cas Number:
Molecular formula:
C29 H44 O6
7 beta-Hydroxy-3 beta,15 alpha-dipivaloyloxy-5-androsten-17-one
Details on test material:
- Name of test material (as cited in study report): Dipivalat (ZK 92136)
- Lot/batch No.: 21604815
- Analytical purity: 86.4%

Study design

Oxygen conditions:
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
% degradation (CO2 evolution)
Sampling time:
30 d
Details on results:
Degradation reference compound sodium acetate: 83%
Degradation toxicity control: 45%

Any other information on results incl. tables

Biological degradation (cumulative) in percent (corrected for blank C02-production) of ZK 92136

Day of sampling
 Test compound ZK 92136  Nominal concentration of carbon   4 7 11 16 21 25 30
 10 mg/L   0 0 0 1 0 1 2
 Sodium acetate (reference)    10 mg/L   24 43 59 71 77 80 83
 ZK 92136 + sodium acetate (toxicity control)    10 mg/L + 10 mg/L   12 20 28 35 40 42 45

Applicant's summary and conclusion

Validity criteria fulfilled:
Interpretation of results:
inherently biodegradable
In accordance with the OECD guideline, the test compound ZK 92136 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 Dipivalat (ZK 92136), an intermediate of the synthesis of drospirenone. The study was conducted in agreement with the following test guideline: OECD guideline for testing of chemicals, Ready biodegradability: C02-evolution test, no. 301 B, adopted Jul. 92, OECD Paris, 93.

The test substance ZK 92136 was incubated in an aqueous solution in a concentration of 10 mg carbon/I in triplicate including nutrients with microorganisms trom a municipal sewage treatment plant for 28 days.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 ZK 92136 was degraded to 2% on day 30 (28 days of incubation). The reference compound sodium acetate was degraded to 83% on day 30 (28 days of incubation).

In the toxicity control, the reference compound (sodium acetate) plus the test compound ZK 92136 was degraded up to 45% on day 30 (28 days of incubation), thus reflecting the degradation of the substances incubated separately.

In accordance with the OECD guideline, the test compound ZK 92136 is not readily

biodegradable under the conditions of the test and it was not toxic to the microbes of activated sludge.