Ethisterone

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well documented GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Ethisterone

EC Number:

207-096-5

EC Name:

Ethisterone

Cas Number:

434-03-7

Molecular formula:

C21H28O2

IUPAC Name:

(1R,3aS,3bR,9aR,9bS,11aS)-1-ethynyl-1-hydroxy-9a,11a-dimethyl-1H,2H,3H,3aH,3bH,4H,5H,7H,8H,9H,9aH,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-7-one

Sampling and analysis

Analytical monitoring:

yes

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 8.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 8.7

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 3

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 8.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 4

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

> 8.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of Ethisterone (ZK 4957) to Daphnia magna is higher than a saturated solution (8.7 mg/L, as determined by TOC analysis).

Executive summary:

20 juvenile Daphnia magna were used for the test solution of ZK 4957 and 20 for the tap water control. The Daphnia were exposed for a period of 48 hours under static conditions. Immobilization was recorded at 24 hours and 48 hours.

For the preparation of the test solution, a suspension with a nominal loading of 100 mg/L was ultrasonified and stirred for 24 hours. This suspension was filtered through a glass-fiber filter. The saturated solution obtained by this procedure was used for the preparation of the test solution.

The organic carbon concentration of the test solution was analyzed with a TOC analyzer with samples taken at the start of exposure and 48 hours thereafter. The substance concentration was calculated on the basis of the molecular formula. The mean concentration was calculated with 8.7 mg/L.

No immobilization occurred. The EC₅₀/48 hours of ZK 4957 to Daphnia magna is higher than a saturated solution (8.7 mg/L).