(RS)-3-Allyl-2-methyl-4-oxocyclopent-2- enyl (1R,3R)-2,2-dimethyl-3-(2-methyl prop-1-enyl)-cyclopropanecarboxylate (mixture of 2 isomers 1R trans: 1R/S only 1:3) (Esbiothrin)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Purity : 96.8%

Sampling and analysis

Analytical monitoring:

yes

Remarks:

at the begin, 24 and 48 h

Test solutions

Details on test solutions:

Juvenile daphnids were exposed to an aqueous test medium containing the test item at five nominal concentrations in a geometric series (2.0, 6.3, 20.0, 63.2, 200.0 microg/l).
A solvent control was prepared by adding 50 microl acetone to 500 ml of reconstituted water in order to obtain the same solvent concentation of the test solution (100 ul).
A control with reconstituted water only was also tested.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

ACCLIMATION
- Acclimation period:12 days
- Acclimation conditions: same as test

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Post exposure observation period:

Check for immobilisation 24 and 48 h after test initiation

Test conditions

Hardness:

2.5 mmol/L (250.0 mg/l as CaCO3)

Test temperature:

20 +/-2°C with a maximum deviation of +/-1°C during the individual study. 19.0 - 21.0°C.

pH:

7,32 - 7,72

Dissolved oxygen:

6.1 - 7.0 mg/l

Nominal and measured concentrations:

2.0, 6.3, 20.0, 63.2, 200.0 microg/l

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5 µg/L

Nominal / measured:

meas. (geom. mean)

Effect concentrations 2

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

16 µg/L

Nominal / measured:

meas. (geom. mean)

Effect concentrations 3

Key result

Duration:

48 h

Dose descriptor:

IC50

Effect conc.:

9.5 µg/L

Nominal / measured:

meas. (geom. mean)

Remarks on result:

other: 7.5-10.5

Details on results:

The test item concentration was not stable during the test, the measured concentrations being around 55% and 20-40% of the nominal already short after being prepared (time 0 h and time 24 h, fresh solution rescpectively), while further decrease occurrred during the following day (to around 3-30 % of the nominal). Therefore the biological results are not referred to the nominal concentration but to the geometric mean of the measured concentration.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The results, calculated based on the mean of the measured exposure concentrations were as follows:
48h NOEC: 5.0 microg/l
48h LOEC: 16.0 microg/l
48h IC50: 9.5 microg/l (95% confidence range: 7.5 - 10.5 microg/l)