Registration Dossier

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:
14 August - 16 August, 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
White solid

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
Non-GLP preliminary test Gl 7220002A was conducted with the concentrations of 1.0, 10, 50 and 100 mg/L (nominal concentration). As results showed, all daphnids in the control and each concentration group did not appear immoble or with any abnormal behavior.

According to the preliminary test results, the definitive test was conducted with the test item concentration of 100 mg/L (nominal concentration, not adjusted for purity). A concurrent blank control was performed in parallel. 4 replicates were used with 5 daphnia for each replicate.

Test solutions

Vehicle:
not specified
Details on test solutions:
0.5002 g of the test item was weighed and dissolved with test water and made up to SL to get the 100 mg/L administer solution. Test solution was magnetically stirred at 350 rpm for 30 min and then used for exposure. The test solution was distributed into 4 test vessels, and each vessel contained about 100 mL the solution. And then 5 daphnids were put into each vessel for exposure. About 100 ml test water was used for each replicate of the control group.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
The test Daphnia species was Daphnia magna Straus, which is one of the recommended species of the MEP, P.R. Guideline for the Testing of Chemicals.
The test Daphnia magna were derived from teh same healthy stock, and the animals were less than 24 hours old and not first brood progeny. There was no difference between culture conditions of stock animals and the test. The condition for the pre-culture was as below:

Temperature: 18-22°C
Light: 16 hours photoperiod daily, 8 hours dark
Feed: concentrated algal suspension

The batch used for this definitive test was DaphniaC20170814. In the facility, tests with a reference substance of the potassium dichromate (K2Cr2O7)
were conducted four times a year, and all were within the range of 0.6 to 2.1 mg/L. The EC50-24 h of the potassium dichromate to Daphnia was 1.80 mg/L, 95% confidences were 1.63-2.00 mg/L.

Study design

Test type:
static
Water media type:
other: ground water treated with aquapro pure water system
Limit test:
yes
Total exposure duration:
48 h
Post exposure observation period:
Each test vessel was checked for immobilized daphnids at 24 and 48 hours after the beginning of the test. In addition to immobility, any abnormal behavior or appearance was recorded. Those animals that were not able to swim within 15 seconds, after gentle agitationof the test vessel were considered to be immobilised.

Test conditions

Hardness:
The hardness of the test water was 200 mg/L (as CaCO3).
Test temperature:
Determined temperature was 20.9 - 21.1 °C. The monitored temperature was in the range of 20.41 - 2 l .06°Cwithin the range of 18 - 22°C.
pH:
7.13 - 8.17
Dissolved oxygen:
7.49- 7.89 mg/Land
Salinity:
Not specified
Conductivity:
Not specified
Nominal and measured concentrations:
Nominal concentration: 100 mg/L
Measured concentration: 87.232 mg/L
Details on test conditions:
Light: 16 hours photoperiod daily, 8 hours dark
During the test, there was no aerating to vessels, pH regulating or feeding.
Static test system: the test solution was not renewed during the test.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Details on results:
During the 48-hour exposure period, no immobilisation or visible toxic signs were observed in the control and 100 mg/L vessels.
For the 100 mg/L (nominal concentration) test solutions, the determined concentration in fresh media was 80.845 mg/L, while the determined concentration in old media was 82.794 mg/L. The overall determined concentration was 81.820 mg/L. The overall determined concentration was 81.8% of nominal concentration.
Results with reference substance (positive control):
In the facility, tests with a reference substance of the potassium dichromate (K2Cr207) were conducted four times a year, and were all within the range 0.6 to 2.1 mg/L. The EC50-24 h of the potassium dichromate to Daphnia was 1.80 mg/L, 95% confidences were 1.63-2.00 mg/L.
Reported statistics and error estimates:
The effect of the limit concentration was determined directly from the test results.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
According to the immobilisation data of the test, the 48-hour EC50 of Difluorosulfonamide HCl to Daphnia magna was greater than 100 mg/L (nominal concentration).