3'H-Cycloprop[15,16]androst-15-en-17-one, 3-(2,2-dimethyl-1-oxopropoxy)-5,6-epoxy-15,16-dihydro-7-hydroxy-, (3.beta.,5.beta.,6.beta.,7.beta.,15.alpha.,16.alpha.)-

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:

Mar - Apr 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

5,6 beta-Epoxy-7 beta-hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-androstan-17-one

EC Number:

617-351-6

Cas Number:

82544-13-6

Molecular formula:

C25 H36 O5

IUPAC Name:

5,6 beta-Epoxy-7 beta-hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-androstan-17-one

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): municipal sewage treatment plant ("Kläranlage Berlin-Ruhleben")
- Laboratory culture: Schering AG, Ecotoxicology
- Storage conditions: room temperature

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline

TEST SYSTEM
- Culturing apparatus:
- Details of trap for CO2 and volatile organics if used: For the determination of the CO2 produced, three CO2-absorber bottles, filled with 100 mL 0.025 N Ba(OH) each, were connected in series to the exit air-pipe of each test bottle. The amount of CO2 produced was determined by titration of the remaining Ba(OH)2 with 0.05 N standardized HCI. On days 4, 7, 11, 16, 21, 25 and 30 the CO2-absorber bottle nearest to the test bottles was removed for the titration, with the exception of day 30 when all three bottles were removed. The remaining two absorbers were each moved one place closer to the test vessel and a new absorber bottle filled with fresh Ba(OH)2 was placed at the far end of the series.

SAMPLING
- Sampling frequency: sampled on day 4, 7, 11, 16, 21, 25 and 30. On day 29 the solutions were acidified in order to expel all dissolved CO2, and CO2 was determined on day 30.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 3 vessels
- Abiotic sterile control: no
- Toxicity control: yes, 1 vessel

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

30 d

Details on results:

The test compound ZK 90346 was not degraded by day 30 (28 days of incubation).

BOD5 / COD results

Results with reference substance:

The reference substance was degraded to 90.8% after 30 d.

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 90346 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 Methylenepoxidpivalat (ZK 90346), an intermediate of the synthesis of drospirenone. The study was conducted in agreement with the test guideline OECD 301 B, Ready biodegradability: C02-evolution test, adopted Jul. 92, OECD Paris, 93.

The test substance ZK 90346 was incubated in a concentration of 10 mg carbon/L in an aqueous solution including nutrients with microorganisms from a municipal sewage treatment plant for 28 days.

The test compound ZK 90346 was not degraded by 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 contral, the reference compound (sodium acetate) plus the test compound ZK 90346 was degraded up to 41 % on day 30 (28 days of incubation), thus reflecting the degradation of the substances incubated separately.

Accordingly, the test compound ZK 90346 is not readily biodegradable under the conditions of the test and it was not toxic to the microbes of activated sludge.