3β,21-dihydroxy-16α-methylpregn-5-en-20-one 21-acetate

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:

Dec 1994

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:

1995

Report date:

1995

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:

3β,21-dihydroxy-16α-methylpregn-5-en-20-one 21-acetate

EC Number:

214-633-7

EC Name:

3β,21-dihydroxy-16α-methylpregn-5-en-20-one 21-acetate

Cas Number:

1173-09-7

Molecular formula:

C24H36O4

IUPAC Name:

2-[(1S,2R,3aS,3bS,7S,9aR,9bS,11aS)-7-hydroxy-2,9a,11a-trimethyl-1H,2H,3H,3aH,3bH,4H,6H,7H,8H,9H,9aH,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-yl]-2-oxoethyl acetate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): 16Alpha-Methyl-Acetoxypregnenolon
- Lot/batch No.: 14415018
- Analytical purity: 98,9%

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.:

> 1.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Any other information on results incl. tables

Table 1: Cumulative immobilization

	Cumulative immobilization
Concentration of	Total no. of Daphnia	Immobilized Daphnia
ZK 29211		24 hours	48 hours
0 mg/l	20	0	0
1,8 mg/I	20	0	0

Table 2: Concentration analysis by TOC measurement

Test compound	Day 1		Day3
Control vessel	1.6 mg/L TOC		2.9 mg/L TOC
ZK 29211 (test vessel)	3.2 mg/L TOC		4.0 mg/LTOC
Test vessel -control vessel	1.5 mg/L TOC		1.2 mg/L TOC
ZK 29211	2.1 mg/L		1.6 mg/L
Mean value		1.8 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of ZK 29211 to Daphnia magna is higher than a saturated solution
(1.8 mg/L) which was prepared using a suspension corresponding to 100 mg/L nominal loading.

Executive summary:

The purpose of this study was to determine the acute toxicity (immobilization, ECso/48 hours)

of 16Alpha-Methyl-Acetoxypregnenolon (ZK 29211) with Daphnia magna in a limit test in order to evaluate the aquatic toxicity.

The study was conducted in agreement with the guideline of the OECD, no. 202.

20 Daphnia were used for the test solution of ZK 29211 and 20 for the dilution water control.

The Daphnia were exposed to the test solution and the dilution water for aperiod of 48 hours

under static conditions. Immobilization was recorded at 24 and 48 hours.

The nominalloading of the test solution was 100 mg/L. For the preparation of the test solution,

a suspension corresponding to a nominal concentration of 100 mg/L was filtered through a

glassfibre filter.

The organic carbon concentration of the test solution was analysed with a TOC-analyser at

o and 48 hours and the substance concentration was calculated according to the structural

formula. The concentration of the filtered solution was 1.6-2.1 mg/L (mean: 1.8 mg/L).

No immobilized Daphnia were observed in the control or in the test solution.

The EC50/48 hours of ZK 29211 to Daphnia magna is higher than a saturated solution

(1.8 mg/L) which was prepared using a suspension corresponding to 100 mg/I nominal loading.