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Ecotoxicological information

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

Constituent 1
Chemical structure
Reference substance name:
5-Hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-androst-6-en-17-one
EC Number:
617-345-3
Cas Number:
82543-14-4
Molecular formula:
C25 H36 O4
IUPAC Name:
5-Hydroxy-15 beta,16 beta-methylene-3 beta-pivaloyloxy-5 beta-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 concentrationsopen allclose all
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
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.

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