(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17β-ol

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Sept - Oct 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline under GLP

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other 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 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17β-ol

EC Number:

213-860-9

EC Name:

(±)-13-ethyl-3-methoxygona-2,5(10)-dien-17β-ol

Cas Number:

1038-28-4

Molecular formula:

C20H30O2

IUPAC Name:

11a-ethyl-7-methoxy-1H,2H,3H,3aH,3bH,4H,5H,6H,9H,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-ol

Details on test material:

- Name of test material (as cited in study report): Ethyldienol
- Analytical purity: 80.9 to 93.9%
- Lot/batch No.: mixed batches

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

48 h

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1.9 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Any other information on results incl. tables

Table 1:

Dilution of ZK 47569	Concentration of ZK 47569 mg/L	24 hours	48 hours
0 control (tap water)	0	0	0
1:8	n.d.	0	0
1:4	0,52	0	0
1:2	1,25	0	5
Saturated solution	2,96	20	95

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours was calculated with 1.9 mg/L based on TOC analysis. This indicates that
ZK 47569 is toxic to Daphnia magna.

Executive summary:

The purpose of this study was to determine the acute toxicity (immobilization, EC50/48 hours) of

Ethyldienol with Daphnia magna in order to evaluate the aquatic toxicity. Ethyldienol is an

intermediate of the synthesis of ZK 13664 (Norgestrel).

The test compound was hydrolytically unstable (half-life 27.8 hours/pH 7). The study

was conducted in a definitive test (under semi-static conditions) in agreement with the guideline of the OECD, no. 202.

20 juvenile Daphnia magna were used for each of the test solutions of the test compound and 20 for the

tap water control. The Daphnia were exposed to the test solutions and the dilution water for a

period of 48 hours under semi-static conditions (the control and test solutions were renewed 24

hours after start of exposure). Immobilization was recorded at 24 hours and 48 hours.

For the preparation of the test solutions, a suspension with a nominal loading of 100 mg/L was

stirred for 24 hours. This suspension was filtered through a glassfibre filter. The resulting

solution served as the highest concentration (saturated solution). It was further diluted 1 :2, 1:4

and 1 :8. 24 hours after start of exposure the test solutions were renewed.

The chemical analysis of the saturated solution by HPLC showed unexpectedly low concentrations of 6.5 x 10-5 mg/L. Additionally, TOC analysis was performed at 0, 24 and 48 hours. The mean TOC concentration of the saturated solution was 2.4 mg/L corresponding to 2.96 mg/L of test compound. The water solubility of Ethyldienol was determined with 6 mg/L in a standard

test. Therefore, the concentration of Ethyldienol extrapolated from TOC analysis was considered representative.

Statistical evaluation regarding the observations of immobilization was performed by probit analysis on the basis of the organic carbon content.