3-methoxyoestra-1,3,5(10)-trien-17-one

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Dec 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Remarks:

HPLC-UV

Details on sampling:

at 0 h and 96 h

Vehicle:

no

Details on test solutions:

Preparation of the test solution
2.01 g of the test substance were dissolved in 20 L of tap water in the test aquario. This solution was stirred continously for a period of 25 h by an automatic stirrer. After stirring, the solution was filtered under vacuum and filled into the aquario. The measured pH-valu of the filtered solution was 8.5.
For the control group pure tap water was used.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

- Specification: Zebra fish, brachydanio rerio, Hamilton-Buchanan; Teleostei, Cyprinidae
- Soure: German bred; distributor: Südharz-Aquarium, Zierfischzüchterei, Bad Lauterberg
- Size: 2.5 +- 0.5 cm (estimated)
- Holding: The fish were acclimatized for 17 days before start of the test in tap water of the same quality as used for the test. They were fed twice daily and the parameters oxygen content, pH-value and temperature were measured each day.
- Pre-test mortality: One fish was found dead on the first day of acclimatization (equivalent to 4% mortality)
- Water: Normal tap water was used as dilution water, not polluted with harmful concentrations of chlorine, heavy metals or other substances, based on quarterly measurements and according to the criteria of the German drinking water directive.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Test temperature:

21.1 - 21.6°C

pH:

8.1 - 8.4

Dissolved oxygen:

86 - 103 %

Nominal and measured concentrations:

A saturated solution was prepared (1000mg/L) by stirring for 25 h and subsequent filtration
measured concentration: at the beginning 0.026 mg/L, at the end: 0.07 mg/L (difference is probably due to adsorption to the wall of the test vessel

Details on test conditions:

Ten fish were used for the test substance and ten for the control group, randomly distributed into blocks of five. Only fish in good health and free from any apparent malformation were used. Labelled 25 L glass aquaria were used as test vessels.
The fish were exposed to the test substance and the control solution for a period of 96 h under static conditions. The light/dark rythm was adjusted to 12 h/12 h. The test and control solution were not aerated during the exposure.
Mortalities and visible abnormalities were recorded at approx. 3, 6, 24, 48, 72 and 96 h.

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

>= 0.03 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: solubility limit under test conditions

Details on results:

No mortality or visuable abnormality was observed in fish at 3, 6, 24, 48, 72 and 96 hours exposure.

Validity criteria fulfilled:

yes

Remarks:

oxygen concentration >= 60% of the air saturation value, constant conditions were maintained (temperature not deviating by more than 1° C in each test, pH not deviating by more than 1 unit in each test), mortality <=10 %

Conclusions:

Estron-Methylether was not acutely toxic to fish up to the maximum solubility (0.03 mg/L) achieved in the test.

Executive summary:

A study was conducted according to guideline OECD 203 to assess the toxicity of Estron-Methylether towards fish. Ten Zebra fish were used for the test solution and ten for the control group. The fish were exposed to one concentration (saturated solution) and the dilution water for a period of 96 h.

A saturated solution was prepared by suspending 2.0 g of test substance in 20 L of water, under constant stirring over a period of 25 h and subsequent filtration. The saturated solution obtained was used as test solution. The concentration was determind as 0.026 mg/L at the beginning and 0.07 mg/L at the end of exposure. The difference is probably due to adsorption to the wall of the test vessels.

Mortalities and visible abnormalities were recorded at approx. 3, 6, 24, 48, 72 and 96 h. Samples for the analysis by HPLC were taken at 0 and 96 h. The temperature of the test and the control solution was in the range of 21.1 - 21.6 °C, the pH-value was between 8.1 and 8.4 during the exposure. The oxygen content was between 7.6 and 9.1 mg/L (86 - 103%).

No mortality was observed in the control or in the test solution during the whole exposure time. Thus, the 96h-LC50 of Estron-Methylether is higher than a saturated solution (0.026 mg/L).

Description of key information

A study was conducted according to guideline OECD 203 to assess the toxicity of Estron-Methylether towards fish. Ten Zebra fish were used for the test solution and ten for the control group. The fish were exposed to one concentration (saturated solution) and the dilution water for a period of 96 h.

A saturated solution was prepared by suspending 2.0 g of test substance in 20 L of water, under constant stirring over a period of 25 h and subsequent filtration. The saturated solution obtained was used as test solution. The concentration was determind as 0.026 mg/L at the beginning and 0.07 mg/L at the end of exposure. The difference is probably due to adsorption to the wall of the test vessels.

No mortality was observed in the control or in the test solution during the whole exposure time. Thus, the 96h-LC50 of Estron-Methylether is higher than a saturated solution (0.026 mg/L).

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

LC50

Effect concentration:

0.026 g/L