13-β-ethyl-3-methoxygona-2,5(10)-dien-17-one

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:

Jul 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

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

Vehicle:

no

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 1.7 mg/L

Nominal / measured:

meas. (arithm. mean)

Basis for effect:

mobility

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

Validity criteria fulfilled:

yes

Conclusions:

The EC50/48 hours of ZK 28520 to Daphnia magna is higher than a saturated solution
equivalent to 1.7 mg/L as carbon. This includes the presence of hydrolysis products.

Executive summary:

The purpose of this study was to determine the acute toxicity (immobilization, EC50/48 hours) of D-ET-Dienon (ZK 28520) with Daphnia magna in order to evaluate the aquatic toxicity. The study was conducted as a limit test in agreement with the guideline of the OECD, no. 202.

20 juvenile Daphnia magna were used for the test solution of D-ET-Dienon and 20 for the tap water control. The Daphnia were exposed for aperiod of 48 hours under static conditions. Immobilization was recorded at 24 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 saturated solution obtained by this procedure was used. The organic carbon concentration of the test solution was analysed with a TOC analyser at the start of exposure and 48 hours thereafter. The organic carbon concentration was 2.7 mg/L. Additionally, a specific analysis was performed by HPLC. The result shows a concentration lower than the quantification limit of 60 µg/L. The substance is subject to hydrolysis (see Schering report L Y92). In a further study on the stability of ZK 28520 it was shown that the initial concentration of a saturated solution was 27 µg/L with very little change over 72 hours. The comparison of the TOC analysis with the specific HPLC analysis indicated that hydrolysis products of the main substance dominated in the solution.

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

Description of key information

The EC50/48 hours of ZK 28520 to Daphnia magna is higher than a saturated solution

equivalent to 1.7 mg/L as carbon. This includes the presence of hydrolysis products.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 1.7 mg/L