Registration Dossier

Ecotoxicological information

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

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:
20 February 2018 - 23 March 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Qualifier:
according to
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
GLP compliance:
yes (incl. certificate)
Specific details on test material used for the study:
Batch: 53715080
Purity: not supplied
Analytical monitoring:
yes
Details on sampling:
- Concentrations:
Range-finding test - 0.10, 1.0, 10 and 100% v/v saturated solution.
Definitive test - 10, 18, 32, 56 and 100% v/v saturated solution.

- Sampling method: Samples at each concentration were taken at 0 and 48 hours for chemical analysis
- Sample storage conditions before analysis: All samples were stored frozen prior to analysis.
Vehicle:
yes
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A nominal amount of test item (550 mg) was dispersed in 11 liters of test water with the aid of propeller stirring at approximately 1500 rpm for 24 hours. After 24 hours the stirring was stopped and any undissolved test item was removed by filtration through a 0.2 µm Sartorius Sartopore filter (first approximate 2 liters discarded in order to pre-condition the filter) to give a 100% v/v saturated solution.
- Controls: Potassium Dichromate as positive control. Negative control used identical conditions but not exposed to test item.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): Reconstituted water (Elendt M7 medium)
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Source: in-house laboratory cultures.
- Age of parental stock (mean and range, SD): not specified
- Feeding during test: None

ACCLIMATION
Adult daphnids were maintained in 150 mL glass beakers containing 100 mL Elendt M7 medium in a temperature controlled room maintaining the water temperature at 18 to 22 °C.
Lighting cycle: 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.
Each culture was fed daily with a mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension.
Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing.
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Post exposure observation period:
none specified
Test temperature:
20°C to 21°C throughout the test
pH:
0 hours (fresh media): 7.9 - 8.0
24 hours (old media): 7.7 - 8.1
24 hours (fresh media): 8.0 - 8.1
48 Hours (Old Media): 8.1
Dissolved oxygen:
0 hours (fresh media): 8.9 - 9.1 mg O2/L
24 hours (old media): 8.2 - 8.9 mg O2/L
24 hours (fresh media): 8.9 - 9.1 mg O2/L
48 Hours (Old Media): 8.6 - 8.8 mg O2/L
Salinity:
not specified
Conductivity:
not specified
Nominal and measured concentrations:
Nominal: 10, 18, 32, 56 and 100% v/v saturated solution
Measured: 4.3, 7.9, 14, 23 and 42% v/v saturated solution
Details on test conditions:
TEST SYSTEM
- Test vessel: 150 mL glass jars
- Type (delete if not applicable): closed
- Aeration: none
- Type of flow-through (e.g. peristaltic or proportional diluter): semi-static
- Renewal rate of test solution (frequency/flow rate): 24 hours
- No. of organisms per vessel: five daphnids
- No. of vessels per concentration (replicates): four
- No. of vessels per control (replicates): four
- No. of vessels per vehicle control (replicates): four

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods.
- Light intensity: 200 and 1200 Lux

VEHICLE CONTROL PERFORMED: yes

RANGE-FINDING STUDY
- Test concentrations: 0.10, 1.0, 10 and 100% v/v saturated solution
- Results used to determine the conditions for the definitive study: yes
Reference substance (positive control):
yes
Key result
Duration:
24 h
Dose descriptor:
EC50
Effect conc.:
ca. 18 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
ca. 6 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
24 h
Dose descriptor:
LOEC
Effect conc.:
ca. 23 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mobility
Key result
Duration:
48 h
Dose descriptor:
LOEC
Effect conc.:
ca. 4.3 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
The test was considered to be valid given that none of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was equal to or greater than 3 mg/L in the control and test vessels.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: yes
- Limit test: no
- Dose-response test: yes
- EC50: 24 hours 0.79mg/L, 48 hours 0.75 mg/L
- Other: NOEC 0.56 mg/L, LOEC 1.0 mg/L
Reported statistics and error estimates:
LOEC: The slopes and their standard errors of the response curves at 24 and 48 hours were 12 (standard error = 0.018) and 6.3 (standard error = 0.035) respectively.
Validity criteria fulfilled:
not specified
Conclusions:
Exposure of Daphnia magna to the test item has been investigated and gave the following results at 48 hours based on the average freshly prepared test concentrations -
EC50: 6.0 mg/L
95% confidence limits: 5.0 - 7.0 mg/L
LOEC: 4.3 mg/L

Description of key information

Introduction

A study was performed to assess the acute toxicity of the test item to Daphnia magna. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphnia sp., Acute Immobilisation Test" referenced as Method C.2 of Commission Regulation (EC) No. 440/2008.

Methods

Preliminary solubility work conducted indicated that it was not possible to obtain a testable solution of the test item using traditional methods of preparation e.g. ultrasonication and high shear mixing.

A preliminary media preparation trial indicated that a dissolved test item concentration of approximately 36 mg/L was obtained from a saturated solution method of preparation indicating this to be the limit of water solubility of this item under test conditions.

Following a preliminary range-finding test, 20 daphnids (4 replicates of 5 animals) were exposed to an aqueous solution of the test item at nominal concentrations of 10, 18, 32, 56 and 100% v/v saturated solution for 48 hours at a temperature of 20 °C to 21 °C under semi-static test conditions. The test item solutions were prepared by stirring an excess (50 mg/L) of test item in test water using a propeller stirrer at approximately 1500 rpm for 24 hours. After the stirring period any undissolved test item was removed by filtration through a 0.2 μm Sartorius Sartopore filter, first approximate 2 liters discarded in order to pre-condition the filter) to produce a 100% v/v saturated solution of the test item. This saturated solution was then further diluted as necessary, to provide the required test concentrations. Immobilization and any adverse reactions to exposure were recorded after 24 and 48 hours.

Results

Chemical analysis of the fresh test preparations at 0 and 24 hours showed measured test concentrations to range from 4.1 to 42 mg/L. There was no significant change in the measured concentrations of the old or expired media at 24 and 48 hours and so the results are based on the average fresh measured test concentrations only.

Exposure of Daphnia magna to the test item gave the following results based on the average fresh measured test concentrations:

Time Point
(Hours)

EC50
(mg/L)

95% Confidence Limits (mg/L)

LOEC
(mg/L)

48

6.0

5.0

-

7.0

4.3


LOEC =Lowest observed effect concentration

Key value for chemical safety assessment

EC50/LC50 for freshwater invertebrates:
6 mg/L

Additional information