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Ecotoxicological information

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:
Oct - Nov 2000
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: According to OECD guideline under GLP
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2001
Report Date:
2001

Materials and methods

Test guideline
Qualifier:
according to
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

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 1-Alpha-Methylandrostendion
- Analytical purity: 98.7%
- Lot/batch No.: 1365

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.:
ca. 27.1 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.

 Dilution/concentration of ZK 62096 (mg/L)    24 hours    48 hours  
 Control (tap water) / 0 0 0
 1 :16 / 3,5   0 0
 1:8 / 6,3   1 1
 1:4 / 11,3   2 3
 1:2 / 22,0   2 2
 Saturated solution / 33,4   5 20

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The EC50/48 hours of 1-Alpha-Methylandrostendion to Daphnia magna could not be calculated. According to the guideline, the EC50 can be
estimated approximately by the geometric mean of the concentration 22.0 and 33.4 mg/L, which was 27.1 mg/L. The highest concentration with no substance-related effects was 22 mg/L. Accordingly, the compound is slightly toxic to Daphnia magna, since the EC50 was between 10 and
100 mg/L.
Executive summary:

The purpose of the study was to determine the acute toxicity (immobilization, EC50/48 hours) of 1 -Alpha-Methyandrostendion with Daphnia magna in order to evaluate the aquatic toxicity. 1 -Alpha-Methyandrostendion is an intermediate of the synthesis of mesterolone. The study was conducted as a definitive test according to the following guideline of the OECD, no 202.

20 juvenile Daphnia magna were used for each test solution of and 20 for the tap water control. The Daphnia were exposed for aperiod 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 loading of 100 mg/L was kept for approximately 30 min in an ultrasonic bath and 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 :2, 1 :4, 1:8 and 1: 16.

Sampies for the concentration analysis by TOC measurement were taken at 0 and 48 hours after start of exposure. The concentrations were calculated on the basis of the molecular formula. Results gave mean concentrations of 33.4 mg/L (saturated solution), 22.0 mg/L (1:2 solution), 11.3 mg/L (1:4 dilution), 6.3 mg/L (1:8 dilution) and 3.5 mg/L (1 :16 dilution).

Immobilized Daphnia were observed in the dilutions 1:8 up to the saturated solution. The saturated solution was a clear effect level, while at lower concentrations (6.3 to 22.0 mg/L) the lack of a clear exposure-effect relationship suggested that probably some Daphnia were immobilized spontaneously. 1-Alpha-Methylandrostendion is slightly toxic to Daphnia magna, since the EC50 was between 10 and 100 mg/L.