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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:
May 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:
2000
Report date:
2000

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:
7 beta-Hydroxy-3 beta,15 alpha-dipivaloyloxy-5-androsten-17-one
EC Number:
617-708-6
Cas Number:
85390-94-9
Molecular formula:
C29 H44 O6
IUPAC Name:
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)
- Analytical purity: 86%
- Lot/batch No.: 21604812

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:
no
Total exposure duration:
72 h

Results and discussion

Effect concentrations
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

Any other information on results incl. tables

Inhibition of biomass and the growth rate (%) of Scenedesmus subspicatus after 72 hours exposure to ZK 92136

 Dilution of ZK 92136    Inhibition in percent  
 Biomass (integral)    Growth rate  
0  --   -- 
 1 :100   -2,3 -4,5
 1 :50   9,3 0,7
 1 :10   8,7 1,6
 1:2   66,2 28,6
 Saturated solution   78,5 42,3

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
ZK 92136 is very toxic to the green algae Scenedesmus subspicatus (EC50 biomass and growth rate <1mg/L).
Executive summary:

The purpose of this study was to determine the effects of the test compound ZK 92136 on the growth of the green algae Scenedesmus subspicatus. ZK 92136 is an intermediate of the synthesis of drospirenone. The study was conducted in agreement with the test guideline OECD no. 201.

The test substance ZK 92136 was incubated in an aqueous solution including nutrients with an aJgae population of Scenedesmus subspicatus tor a test duration of approximately 72 hours. For the preparation of the test solutions a suspension with a nominal loading of 100 mg/L ZK 92136 served as the highest concentration (saturated solution). It was further diluted 1 :2, 1:10, 1 :50, and 1:100 with demineralized water. The organic carbon concentration of a saturated solution was analysed with a TOC analyzer. It was below 1 mg/L. Therefore it is assumed that all test concentrations were <1 mg/L.

ZK 92136 had a concentration-dependent inhibitory effect on the growth of Scenedesmus subspicatus. The EC-values could not be calculated, since the concentration of the test solutions could not be determined. In any case, the EC50 for biomass was below

1 mg/l, and for growth rate, it is expected to be below 1 mg/L. Consequently, ZK 92136 is very toxic to the green algae Scenedesmus subspicatus.

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