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:
2017-03-16 to 2017-05-09
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 guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
Qualifier:
according to
Guideline:
other: Guidance document on aquatic toxicity testing of difficult items and mixtures, OECD series on testing and assessment number 23, December 14, 2000.
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
White to light yellow powder
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: A16FC1793
- Expiration date of the lot/batch: 2018-02-28 (retest date)
- Purity test date: 2016-03-21 (certificate of analysis release date)

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Stability under test conditions: not indicated
- Solubility and stability of the test substance in the solvent/vehicle: 0.34 g/L in water

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: Samples for possible analysis were taken from all test concentrations and the control at t=0 and t=48h. 2.4 mL of volume was taken from the approximate centre of the test vessels. At the end of the exposure period, the replicates were pooled at each concentration before sampling.
- Sample storage conditions before analysis: The samples were stored in a freezer. Additionally, reserve samples of 2.4 mL were taken for possible analysis.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to an expected low water solubility of the test item, saturated solutions (SS) were prepared. The preparation of test solutions started with a loading rate of 100 mg/L applying 3 days of magnetic stirring at room temperature to ensure maximum dissolution of the test item in test medium. This resulted in a clear and colourless dispersion that contained undissolved floating material and precipitate. The obtained mixture was filtered through a 0.45 µm membrane filter (Whatman; RC55) to remove the undissolved fraction. The filter was pre-conditioned with a small volume of test solution that was discarded. The resulting SS was used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the SS in test medium.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): final test solutions were clear and colourless

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water-flea
- Source: in-house laboratory culture with a known history
- Age at study initiation (mean and range, SD): < 24 h (from parental daphnids of more than 2 weeks old, maximum age 4 weeks)
- Method of breeding: 250 newborn daphnids (i.e. less than 3 days old) are placed into 5 liters of medium in an all-glass culture vessel. Medium is M7. After 7 days of cultivation half of the medium is renewed twice a week.
- Feeding during cultivation: fresh water algae, daily
- Feeding during test: no

ACCLIMATION
- Acclimation period: not relevant

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
180 mg/L as CaCO3
Test temperature:
20°C
pH:
At t=0h: 7.9 - 8.4
At t=48h: 7.9
Dissolved oxygen:
At t=0h: 8.9-9.0
At t=48h: 9.0-9.2
Salinity:
not relevant
Nominal and measured concentrations:
Range finder:
Nominal concentrations: 1, 10 and 100% of SS (10% not analysed)
Measured concentrations (mg/L) at t=0h: 0.589, 53.3
Measured concentrations (mg/L) at t=48h: 0.576, 53.6

Final test:
Nominal concentrations: Solutions containing 1.0, 2.2, 4.6, 10 and 22% of a SS prepared at 100 mg/L
Measured concentrations (mg/L) at t=0h: n.d., 0.989, 2.16, 4.43, 9.85, 22.0
Measured concentrations (mg/L) at t=48h: n.d., 0.951, 2.11, 4.32, 9.64, 21.6
Details on test conditions:
TEST SYSTEM
- Test vessel: beaker
- Material, size, headspace, fill volume: 60 mL, glass beaker filled with 50 mL
- Aeration: not during the test
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Test medium: adjusted ISO medium

OTHER TEST CONDITIONS
- Photoperiod: 16h light daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobility was defined as those organisms which are not able to swim within 15 seconds after gentle agitation of the test container and was monitored after 24 and 48 hours of continuous treatment with the test substance.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2.2
- Range finding study
- Test concentrations: 1, 10 and 100% of a SS prepared at a loading rate of 100 mg/L (setup: combined range finder/limit test)
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
6.4 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 95% C.L.: 5.1-8.1 mg/L
Details on results:
- Mortality of control: none
- Other adverse effects control: no
- Abnormal responses: none
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Mortality: no
- EC50/LC50: 48-h EC50 = 0.48 mg/L. The sensitivity of the daphnids was within the range determined with the historical data collected at Charles River Laboratorie Den Bosch.
Reported statistics and error estimates:
The 24 and 48h-EC50 values were calculated from the probits of the percentages of affected daphnids and the logarithms of the corresponding test item concentrations (analytically confirmed nominal concentration) using the maximum likelihood estimation method.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The acute toxicity of T000841 to Daphnia magna was determined in a 48 hour static test according to OECD guideline 202. Based on analytically confirmed nominal exposure concentrations, the 48-h EC50 was 6.4 mg/L (95% confidence interval between 5.1 and 8.1 mg/L). The results of the test can be considered reliable without restriction.