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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:
22 Jan - 24 Jan 2018
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:
April 13, 2004
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: all concentration levels and control
- Sampling method: Approx. 10 mL of test solution was sampled from the middle layer of each test vessel. Sampling was performed at the start of exposure, before and after the renewal at 24 h and at the end of exposure.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The treatment solutions were prepared as water accommodated fractions (WAFs). The test sample and dilution water were mixed to prepare each nominal loading rate and subsequently stirred for 48 hours. The suspensions were filtered with a membrane filter (0.45 µm pore size). The stirred filtrates were used as test solutions.
- Eluate: no
- Differential loading: yes
- Controls: blank control, reference control
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): After filtration, the test solutions were clear.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: water flea
- Source: The University of Sheffield, United Kingdom; supplied on July 9, 1990
- Age of parental stock: 20 d
- Feeding during test: no
- Breeding conditions of parental stock: breeding in dechlorinated tap water at 20 ± 1 °C; photoperiod: 16 h light/8 h darkness; survival of parental stock: 95%; during breeding, the daphnids were fed Chlorella vulgaris once a day (corresponding to 0.1-0.2 mg organic carbon per day)
- Age of daphnids for test: less than 24 h

ACCLIMATION
- Acclimation period: not specified

Study design

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

Test conditions

Hardness:
32 mg/L (Ca, Mg)
Test temperature:
20.0 - 20.1 °C
pH:
7.8 - 7.9
Dissolved oxygen:
Control: 7.8 - 8.6 mg/L
Treatment: 7.3 - 8.6 mg/L
Conductivity:
13 mS/m
Nominal and measured concentrations:
nominal: Control, 9.5, 17, 31, 56 and 100 mg/L
measured: < detection limit, 0.936, 7.45, 13.4, 33.0 and 61.2 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 100 mL glass beaker, covered with transparent plastic lid
- Renewal rate of test solution: fresh test solutions were prepared after 24 h
- 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
- Total organic carbon: < 0.5 mg/L
- Particulate matter: < 1 mg/L
- Chlorine: < 0.02 mg/L
- Alkalinity: 36 mg/L
- Ca/mg ratio: 4.14
- Conductivity: 13 mS/m
- Culture medium different from test medium: same as test medium
- Intervals of water quality measurement: pH value, temperature and dissolved oxygen concentration were measured at test start, before and after the renewal at 24 h and at test end

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h light/8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable)
- Immobility and behavioural effects were observed after 24 and 48 h.

RANGE-FINDING STUDY
- Concentrations: 100 mg/L (nominal)
- Results used to determine the conditions for the definitive study: After 48 h, 10% immobility was observed at a nominal concentration of 100 mg/L.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate; tested regularly

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 61.2 mg/L
Nominal / measured:
meas. (geom. mean)
Conc. based on:
test mat.
Remarks:
WAF
Basis for effect:
mobility
Remarks on result:
other: 95% CI not determined
Duration:
48 h
Dose descriptor:
EL50
Effect conc.:
> 100
Nominal / measured:
nominal
Conc. based on:
test mat.
Remarks:
WAF
Basis for effect:
mobility
Remarks on result:
other: 95% CI not determined
Details on results:
- Behavioural abnormalities: No immobility and no abnormal behaviour was observed at any exposure level.
- Immobility of control: 0%
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No, the test solutions were clear and colourless at test start and end.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- EC50 (48 h) = 0.12 mg/L (mean ± 2 S.D.: 0.10 - 0.35 mg/L)
Reported statistics and error estimates:
Since no more than 50% immobility could be obtained in any exposure level, the EC50 was estimated as ">maximum test concentration". The estimation of the EC50 was performed based on the geometric mean of the measured concentration of the test solution during exposure.

Any other information on results incl. tables

Table 1: Immobility

Measured concentration [mg/L]

Vessel

24 hours

48 hours

No. of immobilied daphnids/Total daphnids

Immobility [%]

No. of immobilied daphnids/Total daphnids

Immobility

Control

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

0.936

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

7.45

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

13.4

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

33.0

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

61.2

A

0/5

0

0/5

0

B

0/5

0/5

C

0/5

0/5

D

0/5

0/5

 

Table 2: Measured concentrations of the test item in test solutions

Nominal concentration

Measured concentration [mg/L]

Percentage of measured concentration versus that at each preparation [%]

At test start

24 hours

At test end

Geometric mean

Before renewal

After renewal

Control

n.d.

n.d.

n.d.

n.d.

-

9.5

1.70

0.679

(39.9)

0.994

0.668

(67.2)

0.936

17

6.46

5.90

(91.4)

8.98

9.02

(100)

7.45

31

14.1

12.5

(88.5)

13.3

13.9

(104)

13.4

56

31.8

29.7

(93.5)

34.5

36.2

(105)

33.0

100

68.5

63.0

(92.0)

56.9

57.2

(100)

61.2

Table 3: Validity criteria

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.

≥7.3 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”.