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

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

other information

Study period:

Oct-Dec 1998

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:

1998

Report date:

2002

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

5-hydroxy-15β,16β-methylene-3β-pivaloyloxy-5β-androst-6-en-17-one

EC Number:

617-345-3

Cas Number:

82543-14-4

Molecular formula:

C25H36O4

IUPAC Name:

5-hydroxy-15β,16β-methylene-3β-pivaloyloxy-5β-androst-6-en-17-one

Details on test material:

- Name of test material (as cited in study report): Enpivalat (ZK 90504)
- Analytical purity: 91.9%
- Lot/batch No.: 21608604

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Any other information on results incl. tables

The saturated solution (< 1mg/L) showed a inhibition of approximately 30% for biomass and growth rate.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

ZK 90504 had a slight inhibitory effect on biomass and growth rate of Scenedesmus subspicatus at the maximum solubility in water.

Executive summary:

The purpose of this study was to determine the effects of the test compound Enpivalat (ZK 90504) on the

growth of the green algae Scenedesmus subspicatus. ZK 90504 is an intermediate of the synthesis of Drospirenone. An additional study with one test concentration was performed since in the first test the growth in the controls were not within the required quality criteria.

The study was conducted in agreement with the test guideline OECD no. 201.

For the preparation of the test solutions a suspension with a nominal loading of 100 mg/L ZK 90504 was stirred for 24 hours at room temperature. The resulting solution served as the highest concentration (saturated solution) It was further diluted 1 :10, 1 :100 and

1 :1000 with demineralized water .

The saturated solution showed a inhibition of approximately 30% for biomass and growth rate, which was considered slightly

inhibitory, since it was still below 50%, the toxicity criterion used for classification purposes.

EbC50/72 hours (biomass) and the ERC50 (growth rate) could not be calculated, since 50% inhibition was not reached. In comparison to the growth of the control algae, ZK 90504 had a slight inhibitory effect on biomass and growth rate of Scenedesmus subspicatus at the maximum solubility in water. Consequently, ZK 90504 is only slightly toxic to the green algae Scenedesmus subspicatus up

to its solubility limit.