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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:
18 Dec - 20 Dec 2017
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 guideline
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
2004
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: All test concentrations incl. control
- Sampling method: Samples were taken at the beginning and end of exposure period.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test sample (0.150 g) was dissolved in dilution water (1500 mL) to prepare the stock solution of 100 mg/L. Required volumes of the stock solution and dilution water were mixed and stirred in a preparation container to prepare the test solution which was divided into each test vessel. The 100 mg/L test solution was prepared by direct addition.
- Eluate: no
- Differential loading: no (except for the highest test concentration)
- Controls: yes, test medium control
- Evidence of undissolved material: no

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: The University of Sheffield, UK (obtained 9 July 1990)
- Age of daphnids: < 24 h
- Feeding during test: none

ACCLIMATION
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: Chlorella vulgaris of 0.1-0.2 mg C (Organic carbon content)/day.
- Feeding frequency: daily

Study design

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

Test conditions

Hardness:
32 mg/L
Test temperature:
19.9 - 20.2 °C
pH:
7.8 - 8.0
Dissolved oxygen:
8.7 - 9.0 mg O2/L
Conductivity:
13 mS/m
Nominal and measured concentrations:
nominal: control, 9.53, 17.1, 30.9, 55.6, 100 mg/L
Measured (geometric mean): < LOD, 8.65, 16.1, 29.6, 52.1, 97.0 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 mL glass beaker covered with a transparent plastic lid (incubated in a water bath with automatic warming/cooling unit)
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water
- Culture medium different from test medium: no
- Intervals of water quality measurement: Water quality was measured in regular intervals (temperature, O2, pH).

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light / 8 h darkness
- Light intensity: room light

EFFECT PARAMETERS MEASURED
- Immobilisation was measured after 24 and 48 h.

RANGE-FINDING STUDY
- Test concentrations: 1, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: 100% immobilisation was recorded at 100 mg/L whereas no immobilisation was observed at 1 and 10 mg/L. The measured test concentrations during range finder were in the range of 93.2 - 105% of nominal.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate was periodically tested in a 48 hour test design.

Results and discussion

Effect concentrations
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
74.6 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Mortality of control: 0%
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The test solutions were clear and colorless.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- Relevant effect levels: EC50 (48 h) 0.12 mg/L
- Other: Test was conducted from 18 - 20 Oct 2017.
Reported statistics and error estimates:
The EC50 value was calculated using Excel by binominal analysis.

Any other information on results incl. tables

The measured test concentrations were in the range of 80 - 120% of nominal (81.5 - 101%; see Table 2). Thus, it is justified that the effect concentrations were based on the nominal concentrations.

Table 1: Immobilisation of Daphnia magna after 24 and 48 h of exposure.

Nominal concentration [mg/L]

Vessel

24 h

48 h

Number of immobilized Daphnids/total Daphnids

%

Number of immobilized Daphnids/total Daphnids

%

Control

A

0 / 5

0

0 / 5

0

B

0 / 5

0 / 5

C

0 / 5

0 / 5

D

0 / 5

0 / 5

9.53

A

0 / 5

0

0 / 5

0

B

0 / 5

0 / 5

C

0 / 5

0 / 5

D

0 / 5

0 / 5

17.1

A

0 / 5

0

0 / 5

0

B

0 / 5

0 / 5

C

0 / 5

0 / 5

D

0 / 5

0 / 5

30.9

A

0 / 5

0

0 / 5

0

B

0 / 5

0 / 5

C

0 / 5

0 / 5

D

0 / 5

0 / 5

55.6

A

0 / 5

0

0 / 5

0

B

0 / 5

0 / 5

C

0 / 5

0 / 5

D

0 / 5

0 / 5

100

A

3 / 5

80

5 / 5

100

B

5 / 5

5 / 5

C

4 / 5

5 / 5

D

4 / 5

5 / 5

Table 2: Measured concentrations (mg/L + % of nominal) after 0 and 48 h of exposure)

Nominal concentration [mg/]

Measured concentration [mg/L] (%)

0 h

48 h

Geometric mean

Control

Not detected

Not detected

-

9.53

9.63

(101)

7.77

(81.5)

8.65

(90.7)

17.1

17.1

(100)

15.1

(88.3)

16.1

(94.1)

30.9

30.8

(99.8)

28.4

(91.9)

29.6

(95.8)

55.6

56.3

(101)

48.3

(86.9)

52.1

(93.8)

100

97.9

(97.9)

96.1

(96.1)

97.0

(97.0)

Table 3: Validity criteria for OECD 202.

Criterion from the guideline

Outcome

Validity criterion fulfilled

In the control, including the control containing the solubilising agent, not more than 10% of the daphnids should have been immobilized.

 0%

 yes

The dissolved oxygen concentration at the end of the test should be ≥ 3 mg/L in control and test vessels.

 8.7 - 9.0 mg/L

 yes

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
For further details please refer to “Any other information on results incl. tables”.