3'H-Cyclopropa[1,2]pregna-1,4,6-triene-3,20-dione, 1,2-dihydro-17-hydroxy-, (1.alpha.,2.alpha.)-

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:

Feb 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)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione

EC Number:

606-682-1

Cas Number:

2098-65-9

Molecular formula:

C22 H28 O3

IUPAC Name:

17-Hydroxy-1 alpha,2 alpha-methylene-4,6-pregnadiene-3,20-dione

Test material form:

solid: bulk

Sampling and analysis

Analytical monitoring:

yes

Remarks:

TOC-measurement

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 100 mg of ZK 12126 were suspended in 1 L tap water under constant stirring for 24 hours. This suspension was filtered through a fibreglass filter (pore size 0.45 µm). The filtrate was used as highest test concentration and was further diluted with tap water 1:10 and 1:100 to prepare the appropriate concentrations.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: Schering AG, Institute for Experimental Toxicology
- Age at study initiation (mean and range, SD): < 24 h

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Test temperature:

start: 20.8 - 21.3 °C
end: 19.1 - 19.2 °C

pH:

start: 7.8
end: 8.7

Dissolved oxygen:

start: 8.2 - 8.8 mg/L
end: 8.7 mg/L

Nominal and measured concentrations:

nominal: 100 mL (saturated solution)
measured: 6 mg/L (TOC)

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL test vessels
- Volume of solution: 50 mL
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: according to guideline

OTHER TEST CONDITIONS
- Photoperiod: 12 h light/12 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Mobility after 24 and 48 h

Reference substance (positive control):

no

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 6 mg/L

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) after exposure to 1,2 Methylen-4,6 -Dien

Dilution	Concentration of ZK 12126	24 hours	48 hours
Control	0,0 mg/I	0	1
1:100	0,1 mg/I 2)	0	0
1:10	0,6 mg/I 2)	0	0
Saturated Solution	6,0 mg/I 1)	2	2

1) mean of two time-points, 2) extrapolated from highest concentration

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of 1,2 Methylen-4,6-Dien to Daphnia magna is higher than a saturated solution
(equivalent to 6.0 mg/L measured by TOC analysis).

Executive summary:

The purpose of this study was to determine the acute toxicity (immobilization, EC50/48 hours) of 1,2-Methylen-4,6-Dien to Daphnia magna. The study was conducted in agreement with the test guideline of the OECD, no. 202, "Daphnia spec., acute immobilization test"; adopted: 04 Apr. 84.

20 juvenile Daphnia magna were used for each test solution and 20 for the tap water control. 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 solution, a suspension 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 1:10 and 1:100.

The organic carbon concentration of the test solutions was analysed with a TOC analyser at the start of exposure and 48 hours thereafter. The analytical results gave a concentration of 6.0 mg/L (saturated solution) based on a calculation using the structural formula of the test substance. The dilutions had concentrations below the detection limit (1 mg/L organic carbon).

The EC50/48 hours of 1,2 Methylen-4,6-Dien to Daphnia magna is higher than a saturated solution (equivalent to 6.0 mg/L measured by TOC analysis).