Pregna-1,4,6-triene-3,20-dione, 17-(acetyloxy)-

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:

Mar - Apr 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline 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)

Version / remarks:

adopted 04 Apr 1984

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

17-Acetoxy-1,4,6-pregnatriene-3,20-dione

EC Number:

607-988-8

Cas Number:

2668-75-9

Molecular formula:

C23 H28 O4

IUPAC Name:

17-Acetoxy-1,4,6-pregnatriene-3,20-dione

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: saturated solution and dilutions (1:2, 1:4, 1:8, 1:10)
- Sampling method: 0 and 48 h all vessels pooled

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: For the stock solution 100 mg ZK 5560 were suspended in 1000 ml tap water and constantly stirred for 24 hours. Thereafter, the suspension was filtered through a glassfibre filter. This solution was used as the highest test concentration. Aliquots of the solution were further diluted 1:2, 1:4, 1:8 and 1:10 with tap water in order to prepare the appropriate test concentrations.
- Eluate: no
- Differential loading: no
- Controls: yes, test medium control

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Age at study initiation (mean and range, SD): less 24 h

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

20.0 - 21.6 °C

pH:

8.0 - 8.8

Dissolved oxygen:

6.4 - 9.4 mg/L

Nominal and measured concentrations:

Nominal: 100, 50, 25, 12.5, 10 mg/L
measured: 13.85, 6.8, 3.43, 1.62, 1.22 mg/L

Details on test conditions:

TEST SYSTEM
20 Daphnia were used for each test solution and 20 for the dilution water control, randomly distributed into blocks of five. LabelIed 100 mL test vessels were used and filled with 45 mL of the test solution or tap water (control group) and 5 mL of the dilution water with the introduction of the Daphnia. The test was performed with 4 repllicates of each test solution and the dilution water control with 5 Daphnia in each vessel. One additional vessel (measurement vessel) without Daphnia for each test and control solution, respectively, was used for the measurements of pH, temperature and oxygen content. The Daphnia were exposed to the test solutions and tap water (control) for a period of 48 hours under static conditions. The light/dark rhythm was adjusted to 12 hours/12 hours.

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

10.7 mg/L

95% CI:

>= 8.8 - <= 14

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Any other information on results incl. tables

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

Measured concentraton of Delta-1,6 -Hydroxyprogesteronacetat (mg/L)	24 hours	48 hours
0 Control (tap water)	5	5
1,2	0	0
1,6	5	15
3,4	0	10
6,8	5	15
13,9	15	75

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of the test substance to Daphnia magna was calculated to be 10.7 mg/L [95% confidence limits (8.8 - 14.0 mg/L)] on the basis of measured concentrations. The highest concentration with no effects was 1.2 mg/L.

Executive summary:

20 Daphnia were used for each test solution of Delta-1,6 -Hydroxyprogesteronacetat and 20 for the dilution water control (tap water). 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 solutions, 100 mg/L of the test substance were suspended in tap water and stirred for 24 hours. This suspension was filtered through a glassfibre filter. The saturated solution obtained by this procedure served as the highest concentration. It was further diluted 1:2, 1:4, 1:8 and 1:10. The test temperature was in the range of 20.0 to 21.6 °C, the pH ranged between 8.0 and 8.8, and the oxygen concentration between 6.4 and 9.4 mg/L. The light/dark rhythm was adjusted to 12 hours/12 hours. Samples for the concentration analysis by HPLC in combination with UV detection were taken at the beginning and 48 hours after start of exposure. The analytical results gave concentrations of 13.9 mg/L (saturated solution), 6.8 mg/L (1:2 dilution), 3.4 mg/L (1:4 dilution), 1.6 mg/L (1:8 dilution) and 1.2 mg/L (1:10 dilution). Immobilized Daphnia were observed in all test solutions except in the lowest concentration. One immobilized Daphnia was observed in the control solution. The EC50/48 hours to Daphnia magna was calculated to be 10.7 mg/L [95% confidence limits (8.8 - 14.0)] on the basis of measured concentrations. The highest concentration with no effects was 1.2 mg/L.