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:
2017-06-03 to 2017-07-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

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:
liquid: viscous
Details on test material:
- Physical state: liquid (viscous)
- Appearance: clear viscous liquid
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: l16DB1991
- Expiration date of the lot/batch: 2018-06-07 (retest date)
- Analytical purity: 81.8% (technical document DS-TEC-128833)

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: not indicated

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Sampling method: Samples for possible analysis were taken form all test concentrations and the control at t=0 and t=48h. 3.2 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 3.2 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 three 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 solution containing undissolved material. This mixture was allowed to settle for a period of approximately one hour and thereafter, the aqueous saturated solution was siphoned off and 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): All 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 specified

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
180 mg/L as CaCO3
Test temperature:
18 - 22°C
pH:
At t=0h: 7.9 - 8.1
At t=48h: 8.0 - 8.0
Dissolved oxygen:
At t=0h: 8.4 - 8.8
At t=48h: 8.4 - 8.5
Salinity:
not relevant
Nominal and measured concentrations:
Range finder:
Nominal concentrations: 10 and 100% of SS
Measured concentrations (mg/L) at t=0h: 7.94, 80,9
Measured concentrations (mg/L) at t=48h: 7.40, 76.1

Final test:
Nominal concentrations: 0, 2.2, 4.6, 10, 22, 46 % of SS
Measured concentrations (mg/L) at t=0h: n.d., 2.05, 4.10, 9.11, 20.00, 42.7
Measured concentrations (mg/L) at t=48h: n.d., 1.90, 3.77, 8.47, 18.7, 39.3

n.d.: not detected
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 CHANGE IF DIFFERENT
- 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: x 2.2
- Range finding study: yes
- Test concentrations: 1.0, 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.:
14 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Remarks on result:
other: 95% C.L.: 12-16 mg/L
Details on results:
- Mortality of control: 0
- 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 = 0.59 mg/L. The sensitivity of the daphnids was within the range determined with the historical data collected at CRL Europe.
Reported statistics and error estimates:
The 24 h-EC50 values were calculated from the Weibull analysis of the percentage of affected daphnids and the logarithms of the corresponding test item concentrations (analytically confirmed nominal concentration) using the maximum likelihood estimation method.
The 48h-EC50-values were calculated from the probits (Probit analysis) 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.
The calculations were performed with ToxRat Professional v. 3.2.1. (ToxRat Solutions® GmbH, Germany).

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The acute toxicity of T001598 to Daphnia magna was determined in a 48 hour static test according to OECD guideline 202. Based on analytically confirmed nominal concentrations, the 48-h EC50 was determined to be 14 mg T001598/L with a 95% confidence interval ranging from 12 to 16 mg/L. The results of the test can be considered reliable without restriction.