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:
20 Oct 2017 - 01 Nov 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Cross-reference
Reason / purpose:
reference to other 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
Deviations:
no
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Appearance: White powder
- Storage condition of test material: At room temperature

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
- Concentrations: Control and all test concentrations
- Sampling method: 1.8 mL taken from the approximate centre of the test vessels, at t=0 h and t=48 h.
- At the end of the exposure period, the replicates were pooled at each concentration before sampling.
- Sample storage conditions before analysis: Samples were stored in a freezer (≤-15°C) until analysis at the analytical laboratory of the Test Facility.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Direct addition to the medium. Test solutions were prepared at the highest concentration of 100 mg/L. No other treatment than vigorous shaking was needed to completely dissolve the test item in medium. Lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. All test solutions were clear and colorless at the end of the preparation procedure.
- Controls: Test medium without test item or other additives.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus 1820
- Source: In-house laboratory culture with a known history
- Age of parental stock: >2 weeks old
- Age at test initiation: <24 hours
- Validity of batch: Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.

CULTIVATION
- Start of each batch: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of M7 medium in an all-glass culture vessel.
- Maximum age of the cultures: 4 weeks
- Renewal of the cultures: After 7 days of cultivation half of the medium twice a week.
- Temperature of medium: 18-22°C
- Feeding: Daily, a suspension of fresh water algae.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
48 h

Test conditions

Hardness:
180 mg/L (as CaCO3)
Test temperature:
19-20°C
pH:
7.8-8.1
Dissolved oxygen:
8.9-9.0 mg/L
Nominal and measured concentrations:
Nominal: 0.10, 1.0, 10 and 100 mg/L
Measured: Only the limit concentration was analyzed: 104 mg/L at t=0 h, 102 mg/L at t=48 h. The measured concentrations were 102-104% of nominal concentrations throughout the test. Therefore, effects parameters were based on nominal concentrations. See Table 1 in 'Any other information on results' for details on the measured concentrations throughout the test.
Details on test conditions:
The test was performed as Combined Limit/Range-Finding test.

TEST SYSTEM
- Test vessel: 60 mL all-glass
- Aeration: no
- Feeding: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2 for 0.10 and 1.0 mg/L; 4 for 100 mg/L
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium, prepared with tap water purified by Reverse Osmosis
- Culture medium different from test medium: yes, M7 medium
- Intervals of water quality measurement: Dissolved oxygen and pH: at beginning and end of the test, for the highest concentration and the control. Temperature: continuously in a temperature control vessel, beginning at the start of the test.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16 h photoperiod daily

EFFECT PARAMETERS MEASURED
- Immobility (including mortality) at 24 hours and at 48 hours.
Reference substance (positive control):
yes
Remarks:
Potassium dichromate (performed Sep 2017)

Results and discussion

Effect concentrations
Key result
Duration:
48 h
Dose descriptor:
EC50
Effect conc.:
> 100 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
mobility
Details on results:
- Behavioural abnormalities: none observed in the Control group.
- Mortality of control: none
- All water quality parameters remained within the requirements as laid down in the study plan throughout the test.
Results with reference substance (positive control):
- Results with reference substance valid? yes
- The 24h-EC50 was 0.59 mg/L with a 95% confidence interval between 0.52 and 0.68 mg/L.
- The 48h-EC50 was 0.41 mg/L with a 95% confidence interval between 0.34 and 0.46 mg/L.
- The actual responses in this reference test with K2Cr2O7 are within the ranges of the expected responses at the different concentrations, i.e. the 48h-EC50 was between 0.3 and 1.0 mg/L. Hence, the sensitivity of this batch of D. magna was in agreement with the historical data collected at the Test Facility.

Any other information on results incl. tables

Table 1: Test Samples

Time of sampling
[hours]

Concentration
[mg/L]

Relative to nominal
[%]

Relative to initial
[%]

Nominal

Analyzed

0

0

n.d.

n.a.

 

 

100

104

104

 

48

0

n.d.

n.a.

n.a.

 

100

102

102

99

n.d. Not detected.

n.a. Not applicable.

Table 2: Number of Introduced Daphnids and Incidence of Immobility

Time (h)

Replicate

Nominal concentration (mg/L)

Control

0.10

1.0

100

0

A

5

5

5

5

B

5

5

5

5

C

5

 

 

5

D

5

 

 

5

Total introduced

20

10

10

20

24

A

0

0

0

0

B

0

0

0

0

C

0

 

 

1

D

0

 

 

1

Total immobilised

0

0

0

2

Effect %

0

0

0

10

 

 

 

 

48

A

0

0

0

0

B

0

0

0

1

C

0

 

 

2

D

0

 

 

1

Total immobilised

0

0

0

4

Effect %

0

0

0

20

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Remarks:
For details on validity criteria, please refer to section 'Overall remarks'
Conclusions:
The 48h-EC50 for Daphnia magna exposed to the test item exceeded a nominal concentration of 100 mg/L.
Executive summary:

In a 48 h acute toxicity test conducted according to OECD guideline 202, Daphnia magna were exposed to the test item at nominal concentrations of 0.1, 1.0 and 10 mg/L (duplicate, 5 daphnids per replicate) and 100 mg/L and an untreated control (both quadruplicate, 5 daphnids per replicate). Measured concentrations were at 102 -104% relative to nominal throughout the test. Therefore, effect parameters were based on nominal concentrations. No immobility was observed in the control and the two lowest test concentrations throughout the test, while 20% effect was observed at the highest concentration after 48 h of exposure. The 48h-EC50 for Daphnia magna exposed to the test item exceeded a nominal concentration of 100 mg/L. The study is considered to be reliable without restrictions.