4-Nitrophenyl 2-(methylsulphonyl)ethanoate

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:

From 19 to 23 July 2021

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Lot number: 4425-191127
Purity: 99.8%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all concentrations
- Sampling method: in 0-hour fresh solutions and 48-hour old solutions
- Sample storage conditions before analysis: stored in refrigerator (2-8 °C)

Vehicle:

yes

Remarks:

water

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 0.1001 g test item was weighed and dissolved in 1000 mL of test water by magnetic stirring for about 5 hours. After the test item was dissolved completely, the solution of 100 mg/L was used to dilute other solutions and for exposure.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: Applied Chemistry Department Pesticide Environmental Evaluation Laboratory of China Agricultural University.
- Age of parental stock (mean and range, SD): less than 24 hours old

ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not): same with test

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

140 to 250 mg/L (as CaCO3)

Test temperature:

18~22oC

pH:

6.0 to 8.5 pH units

Dissolved oxygen:

not less than 3 mg/L during the test period

Nominal and measured concentrations:

Nominal concentrations: 10, 18, 32, 56 and 100 mg/L; Measured concentrations: 11.796, 19.022, 34.288, 65.592, 108.968 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass beakers
- Volume of solution: 50 mL per vessel
- Aeration: no aeration to vessels
- Renewal rate of test solution (frequency/flow rate): no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per vehicle control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The dilution water was tap water after being treated with Aquapro Pure Water System
- Total organic carbon: < 2 mg/L
- Intervals of water quality measurement: 0, 48 h

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 hr light: 8 hr dark
- Light intensity:

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Biological observation: Observation intervals: 24 hours and 48 hours after exposure.
Method: Each test vessel was checked for immobilized daphnids. In addition to immobility, any abnormal behavior or appearance were recorded. Those animals that are not able to swim within 15 seconds, after gentle agitation of the test vessel are considered to be immobilized (even if they can still move their antennae).

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: During the period of 48 hours, no immobilization or any toxic signs were observed in the control group and the test groups of 0.1, 1, 10 mg/L. 100% immobilization occurred in the test group of 100 mg/L after 24 hours.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

28.43 mg/L

95% CI:

24.88 - 32.5

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

Physicochemical Measurements in the Definitive Test:
The determined values of dissolved oxygen were 8.20 ~ 8.58 mg/L, the pH values were between 7.78 ~ 8.20 and the max difference was 0.42. Hardness of test water measured was 160 mg/L (as CaCO3). The temperature was 19.1 ~ 20.0 oC, the difference was 0.9 oC.

Toxic Signs in the Definitive Test:
During the 48-hour exposure period, no immobilization and abnormal behavior or appearance was observed in the control group and the test group of 10 mg/L, the daphnids exposed to 18 and 32 mg/L test groups showed abnormal behavior such as immobilization, 100% inhibition occurred in 56 and 100 mg/L test groups after 48 hours.

Verification of Test Concentration in the Definitive Test:
The concentrations of test item were determined in samples of test media by HPLC method. Analysis of the concentration of the test item were performed in 0 hour fresh solutions and 48 hours old solutions. The results showed that the determined concentrations in 0-hour fresh media were 105.7% ~ 118.0% of nominal concentrations, the determined concentrations in 48 hours old media were 110.9% ~ 118.1% of nominal concentrations. The test concentrations were satisfactorily maintained in the range of 80 - 120% of nominal concentration.

Results with reference substance (positive control):

EC50-24 h of potassium dichromate to Daphnia magna was 1.54 mg/L, and the 95% confidence limits was 1.34 ~ 1.79 mg/L. The results met the recommended criterion in OECD Guideline No. 202: EC50-24 h of potassium dichromate is within the range of 0.6 mg/L to 2.1 mg/L.

Validity criteria fulfilled:

yes

Conclusions:

The 48-hour EC50 of the test item to Daphnia magna was determined to be 28.43 mg/L.

Executive summary:

A Daphnia acute immobilization test of the substance was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 28.43 mg/L.

Description of key information

A Daphnia acute immobilization test of the substance was conducted with Daphnia magna over a 48-hour exposure period, according to OECD Guideline 202.

The 48-hour EC50 of the test item to Daphnia magna was determined to be 28.43 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

28.43 mg/L