1-(3-Chloro-2-pyridinyl)-4,5-dihydro-3-[(phenylsulphonyl)oxy]-1H-pyrazole-5-carboxylic acid ethyl ester

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:

March 2007 - June 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

adopted 29 December 1992

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

adopted 13 April 2004

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

ethyl 3-[(benzenesulfonyl)oxy]-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate

EC Number:

846-153-4

Cas Number:

653592-41-7

Molecular formula:

C17H16ClN3O5S

IUPAC Name:

ethyl 3-[(benzenesulfonyl)oxy]-1-(3-chloropyridin-2-yl)-4,5-dihydro-1H-pyrazole-5-carboxylate

Test material form:

solid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Sampling method: One sample from the freshly prepared test media of the test concentration and the negative and vehicle controls were taken at the start of the test. For the determination of the stability of the test item under the test conditions, one sample from the test concentration and the controls were collected at the end of the test by pouring together the contents of the test beakers of each treatment.

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solution: A 100 mg sample of the test item was weighed into a 10 mL volumetric flask and brought to volume with the vehicle acetone (10000 mg/L).
The test solution was prepared by diluting a calculated amount of the stock solution with test medium.
- Controls: Negative control: Test medium; vehicle control: 100 μL acetone was made up to 1 L using test medium.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation: Less than 24 hours
- Source: Local pond at Peenya 2nd stage, Bangalore, INDIA. Bred at Department of Safety Assessment , Advinus Therapeutics Private Limited, Bangalore, INDIA (For ~10 years)
- Feeding during test: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

Total hardness as CaCO3: 2.41 mmol/L

Test temperature:

20.0 - 21.0ºC

pH:

7.60 - 7.96

Dissolved oxygen:

> 82% of air saturation value

Nominal and measured concentrations:

Nominal concentration: 1.0 mg/L
Mean measured concentration: 0.71 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass beakers
- Fill volume: 150 mL
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Reconstituted water prepared according to guideline
- Culture medium different from test medium: no
- Intervals of water quality measurement: Dissolved oxygen concentration and pH were measured at the start and end of the test. The measurements of the test solutions at the start were taken in the absence of Daphnia and the end measurements were made in the presence of Daphnia, after pooling the test solutions from 4 replicates of each group.

OTHER TEST CONDITIONS
- Photoperiod: 16/8 hours light/dark cycle
- Light intensity: 1050-1080 Lux

EFFECT PARAMETERS MEASURED: The immobility of daphnids was determined by visual controls after 24 and 48 hours. The number of immobile daphnids in each group was recorded.

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0.01, 0.1 and 1.0 mg/L
- Results used to determine the conditions for the definitive study: After 48 hours test duration in the controls (negative and vehicle) and the test concentrations of 0.01, 0.1 and 1.0 mg/L no immobilization was determined. The definitive study was therefore conducted as a limit test at the solubility of the test item, 1.0 mg/L.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (0.32 mg/L)

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 0.71 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

act. ingr.

Basis for effect:

mobility

Details on results:

The exposure of daphnids to the mean measured concentration of 0.71 mg/L resulted in no immobilization at the end of 48 hours. Also, no immobility was observed in the negative or the vehicle control. The observed NOEC, LOEC and EC50 values were greater than 0.71 mg/L based on the mean measured concentration.

Results with reference substance (positive control):

- Results with reference substance valid? Yes
There was 30 and 80 percent immobilization of Daphnia in the positive control group at 24 and 48 hours after test initiation, respectively, demonstrating the sensitivity of the test procedure. These values are typical for this positive control.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

No immobilization was observed in the negative as well as vehicle control at the end of the test. The dissolved oxygen concentration of the test medium was greater than 82% of the air saturation value.

Conclusions:

The acute toxicity of the test item to Daphnia magna was assessed in a static limit-test. The 48-hour NOEC was determined to be at least 0.71 mg/L (mean measured concentration). The 48‑hour LOEC and the 48-hour EC50 were > 0.71 mg/L (mean measured concentation).

Executive summary:

The acute toxicity of the test item to Daphnia magna was determined in a static 48-hour immobilisation limit test. The test was conducted in accordance with OECD Guideline 202.

The daphnids were exposed to at a nominal concentration of 1 mg/L test item over a 48-hour period. A concurrent negative control (dilution water only), a vehicle control (acetone) and a positive control (potassium dichromate) were also tested. HPLC analysis of the test solutions showed reduction in the measured concentration of the test item in the test media at the end of the treatment period compared to the nominal concentration. Hence, the results are reported based on the mean measured concentration of the test item.
The test solutions were observed for immobilisation of Daphnia at 24 and 48 hours after test initiation. The exposure of daphnids to the mean measured concentration of 0.71 mg/L resulted in no immobilization at the end of 48 hours. Also, no immobility was observed in the negative as well as vehicle control. The observed NOEC, LOEC and EC50 values were greater than 0.71 mg/L based on the mean measured concentration.