Registration Dossier

Diss Factsheets

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
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
Qualifier:
according to guideline
Guideline:
EU Method C.2 (Acute Toxicity for Daphnia)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Analytical monitoring:
no
Details on sampling:
No analytical verification or sampling conducted.
Vehicle:
no
Details on test solutions:
Since the test item is a UVCB (with some constituents likely to be poorly soluble), the test solutions were prepared, separately for each test concentration, through 96-h stirring followed by filtration. The respective amounts of a test item stock solution, prepared in solvent (ethanol) were added to empty glass vessels. So that the total amount of solvent is equal in all test vessels (i.e. equal to that of the highest concentration), the corresponding additional amount of pure solvent was added as well.

After complete evaporation of the solvent (no solvent remaining), the Daphnia medium was added. These mixtures were moderately stirred for 96 h, followed by filtration. The resulting solutions were used as test solutions in the toxicity test.

In the blank controls, pure solvent (ethanol) in a quantity equal to the one used for the highest test concentration was added and evaporated before addition of the Daphnia medium, followed by 96-h stirring and filtration.
Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus (1820)
- Source: Not specified
- Age of parental stock (mean and range, SD): Not first brood progeny
- Feeding during test: No
- Food type: NA
- Amount: NA
- Frequency: NA

ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: Suspension of Desmodesmus subspicatus in Elendt M4 medium with an optical density OD680 of about 15 units.
- Feeding frequency: Not specified
- Health during acclimation (any mortality observed): Not specified

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Not specified (although age less than 24 hours).
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h
Hardness:
252 mg/L (as CaCO3)
Test temperature:
Target: 18 to 22 °C, controlled at ±1 °C
pH:
6 to 9. The pH should normally not vary by more than 1.5 units in one test.
Dissolved oxygen:
> 5 mg/L
Salinity:
Not specified
Conductivity:
<1.5 μS/cm
Nominal and measured concentrations:
Nominal (loading rates): 1.94, 4.27, 9.39, 20.7, 45.5 and 100 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 mL Glass beaker
- Type (delete if not applicable): Covered with a glass plate.
- Material, size, headspace, fill volume: 50 mL per vessel
- Aeration: No
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 3
- No. of vessels per vehicle control (replicates): NA
- Biomass loading rate: Not specified

TEST MEDIUM / WATER PARAMETERS
- Elendt M4 medium as per OECD guideline

OTHER TEST CONDITIONS
- Adjustment of pH: Not conducted
- Photoperiod: 16 hour light.
- Light intensity: Not specified

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobility (24 and 48 hours). Any abnormal behaviour or appearance was noted.

VEHICLE CONTROL PERFORMED: Controls included.

RANGE-FINDING STUDY
- Test concentrations: 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: Yes, results showed high immobility at 100 mg/L.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
106 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat. (total fraction)
Basis for effect:
mobility
Remarks on result:
other: Confidence limits: 78.7 to 171 mg/L
Details on results:
A repeat definitive test was conducted as the inital test showed different results compared with the range-finder. The repeat test showed consistency with the initial definitive test and was reported as the main test.

Results with reference substance (positive control):
The EC50 value for the control of sensitivity for 24 h of exposure with potassium dichromate was estimated to be 0.84 mg/L (data from 24 January 2017), which lies within the recommended range of 0.6 to 2.1 mg/L according to OECD Guideline 202.
Reported statistics and error estimates:
A regression model was used (Weibull) and Chi squared test to determine the EC10 and EC50 where appropriate.

Daphnia immobilisation:

Loading rate (mg/L)

Replicate

Number of individuals

Immobile Daphnids (No./vessel) 24 hour

Immobile Daphnids (No./vessel) 48 hour

% immobile Daphnids after 24 hours

% immobile Daphnids after 48 hours

0

A

20

0

1

0

5

B

20

1

1

5

5

C

20

0

0

0

0

1.94

A

20

0

1

0

5

B

20

0

0

0

0

4.27

A

20

0

1

0

5

B

20

0

0

0

0

9.39

A

20

0

0

0

0

B

20

0

0

0

0

20.7

A

20

0

2

0

10

B

20

0

1

0

5

45.5

A

20

1

4

5

20

B

20

1

4

5

20

100

A

20

3

9

15

45

B

20

4

11

20

55

Validity criteria fulfilled:
yes
Remarks:
Control immobilisation was < 10% and O2 concentrations at the end of the test were satisfactory.
Conclusions:
The 48 hour EL50 value based on nominal loading rates of the substance to Daphnia magna was 106 mg/L.

Description of key information

The 48 hour EL50 value based on nominal loading rates of the substance to Daphnia magna was 106 mg/L. This is used as the key value for chemical safety assessment. No testing on marine species has been conducted and is not required.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
106 mg/L

Additional information

Categories Display