3-methoxyestra-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:

Jan - Feb 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:

1996

Report date:

1996

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:

3-methoxyestra-2,5(10)-dien-17β-ol

EC Number:

214-130-2

EC Name:

3-methoxyestra-2,5(10)-dien-17β-ol

Cas Number:

1091-93-6

Molecular formula:

C19H28O2

IUPAC Name:

(1S,3aS,3bR,9bS,11aS)-7-methoxy-11a-methyl-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): Dihydro-Estradiol-Methylether
- Analytical purity: 89.7 - 90.1%
- Lot/batch No.: 21400234-35

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.08 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 0.07 - 0.10

Any other information on results incl. tables

Table 1: Cumulative immobilization (%) of Daphnia magna (n = 20) after exposure to ZK 24597

	Immobilization %
Test dilution of ZK 24597	24 hours	48 hours
Control (tap water)	0	0
1 :16 diluted	0	0
1:8 diluted	0	0
1:4 diluted	5	30
1:2 diluted	45	70
Saturated solution	30	85
(0,16 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of Dihydro-Estradiol-Methylether to Daphnia magna was calculated to be 0.08 mg/L [95%
confidence limits (0.07-0.10)] on the basis of the concentrations extrapolated fram the content of the saturated solution and is very toxic to Daphnia magna.

Executive summary:

Twenty juvenile Daphnia magna were used for each test solution of Dihydro-Estradiol-Methylether and twenty for the tap water control. The Daphnia were exposed for aperiod of 48 hours under static conditions. Immobilization was recorded at 24 hours and 48 hours. For the preparation of the test solutions a suspension with a nominal concentration of 100 mg/L was prepared and stirred tor 24 hours. This suspension was filtered through a glassfibre filter. The resulting solution served as the highest concentration. It was further diluted 1 :2, 1 :4, 1:8 and 1 :16. Samples for the concentration analysis by HPLC in combination with UV detection were taken at start of exposure and 48 hours thereafter. The analytical results gave a concentration of 0.16 mg/L (mean of 0 and 48 hours) for the saturated solution. Further concentrations could not be determined due to the analytical method !imitations. Statistical evaluation regarding the observations of immobilization was performed by probit analysis, using extrapolated concentration values based on the saturated solution.

An increasing number of immobilized Daphnia were observed in the test dilutions 1 :4, 1:2 and in the saturated solution. The highest dilution without effects was 1 :8. The EC50/48 hours of the test compound to Daphnia magna was calculated to be 0.08 mg/L [95% confidence limits (0.07-0.10)] on the basis of the concentrations extrapolated from the content of the saturated solution. Accordingly, Dihydro-Estradiol-Methylether is very toxic to Daphnia magna.