Oestr-5(10)-ene-3,17-dione

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Oct 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

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

Analytical monitoring:

yes

Details on sampling:

- Sampling method: SampIes for the concentration analysis by TOC were taken at 0 and 48 hours after start of exposure.
The calculated results derived from TOC analysis gave mean concentrations 18.7 mg/L (saturated solution), 8.0 mg/L (1:2 solution), 5.4 mg/L (1:4 solution) and 1.7 mg/L (1:8 solution).

Vehicle:

no

Details on test solutions:

For the preparation of the test solutions, a suspension with a nominal loading of 100 mg/L was ultrasonified (30 min) and stirred for approximately 24 h. 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, 1:8.

Test organisms (species):

Daphnia magna

Details on test organisms:

Source: Schering AG, exp. Toxicology, Berlin, Germany
Age: 0-24 h
Holding: parent animals were kept in glass vessels in water of the same quality and temperature as the experimental conditions. The animals were fed continuously with a laboratory culture of microalgae, e.g. Chorella vulgaris. Normal tap water was used as holding water, not polluted with harmful quantities of chlorine and organochlorine compounds, based on quartely measurements.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

264 mg/L CaCO3

Test temperature:

21.3 - 21.6 °C. This is within the accepted range.

pH:

The pH varied between 7.1 and 7.2 at the beginning of the test and between 8.0 and 8.4 at the end of the test. There was a variation of more than one unit of pH from the beginning of the test to the end in all concentrations. However, this does not need to be considered especially as this is most likely not substance-related and is nor assumed to have an effect of the daphnids.

Dissolved oxygen:

8.5 - 8.9 mg O2/L. This was within the accepted range.

Conductivity:

727 µS/cm

Nominal and measured concentrations:

A saturated solution of a nominal 100 mg/l was used, this was then diluted 1:2, 1:4 and 1:8. The highest measured concentration was 18.7 mg/L, then 8.0, 5.4 and 1.7 mg/L.

Details on test conditions:

TEST SYSTEM
- No. of organisms per vessel: 20

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline
- Culture medium different from test medium: no

OTHER TEST CONDITIONS
- Photoperiod: 12 h ligh/12 h darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Mobility was measured after 24 and 48 h.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 18.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The EC50 (48 h) was slightly higher than the highest observed concentration (18.7 mg/L), which corresponds to the maximum solubility under the conditions of this test. This agreed well with the results of the limit test, where 50% of the daphnids were immobilized in the saturated solution.

Results with reference substance (positive control):

No positive control was used.

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

Measured concentration	24 hours	48 hours
(mg/L)
0	0	0
Control (tap water)
1.7	0	0
5.4	0	0
8	0	0
18.7 (saturated solution)	5	40

Validity criteria fulfilled:

yes

Conclusions:

The study resulted in an EC50 (48 h) of > 18.7 mg/L (measured, saturated solution)

Executive summary:

The purpose of the study was to determine the acute toxicity (immobilization, EC50/48 hours) of Delta-5 -Norandrostendion with Daphnia magna in order to evaluate the aquatic toxicity. The study was conducted according to OECD 202.

20 juvenile daphnids were used for each test solution and 20 for the tap water control. The daphnids 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 solutions a suspension with a nominal concentration of 100 mg/L was ultrasonified (30 min) and stirred for approximately 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.

Samples for the concentration analysis by TOC were taken at 0 and 48 hours after start of exposure. The calculated results derived from TOC analysis gave mean concentrations of 18.7 mg/L (saturated solution), 8.0 mg/L (1:2 solution), 5.4 mg/L (1:4 dilution), and 1.7 mg/L (1:8 dilution).

40% of the daphnids were immobilized at the highest test concentration after 48 h. Thus, an EC50 (48 h) of >18.7 mg/L (measured) and >100 mg/L (nominal) resulted.

Description of key information

The study resulted in an EC50 (48 h) > 18.7 mg/L (measured, saturated solution).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 18.7 mg/L