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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:
02 - 04 Jul 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report Date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)
Version / remarks:
13 Apr 2004
Qualifier:
according to
Guideline:
other: OECD series 23 Guidance on aquatic toxicity testing of difficult substances and mixtures
Version / remarks:
2000
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Remarks:
UPLC
Details on sampling:
- Concentrations: All test concentrations and the control at test start (0 h) and test end (48 h).
- Sampling method: 1.2 mL were sampled from the approximate centre of the test vessels. At the end of the exposure period, the replicates were pooled at each concentrations before sampling. Reserve samples of 1.2 mL were additionally taken from all test solutions.
- Sample storage conditions before analysis: In a freezer (≤ - 15 °C) for a maximum of 3 months after delivery of the draft report.

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The preparation of test solutions started with a concentration of 100 mg/L test item in test medium and a 3-d period of magnetic stirring. The obtained mixture was allowed to settle for 3 h. Then, the aqueous saturated solution (SS) was collected by means of siphoning and used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the saturated solution in test medium.
- Controls: Test medium without test item
- Evidence of undissolved material: All test solutions were clear and colorless at the end of the preparation procedure.
- Other: The test item was a colourless to light yellow liquid and was not completely soluble in test medium at the loading rate initially prepared. No correction was made for the purity/composition of the test item.

Test organisms

Test organisms (species):
Daphnia magna
Details on test organisms:
TEST ORGANISM
- Common name: Water flea
- Source: In-house laboratory culture with a known history
- Age at test start: < 24 h from parental daphnids of more than 2 weeks old. The daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress (i.e. > 20% mortality, presence of males, ephippia or discoloration, delay in 1st brood).
- Breeding conditions: Each batch was started with approximately 250 newborn daphnids, i.e. < 3 d old, which were placed in 5 L M7 medium (Elendt 1990) in an all-glass culture vessel. After 7 d of cultivation, half of the medium was renewed twice a week. Temperature: 18 - 22 °C.
- Feeding during breeding: Daily, a suspension of fresh water algae.
- Feeding during test: No

Study design

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

Test conditions

Hardness:
180 mg/L CaCO3 (test medium)
Test temperature:
19 - 20 °C
pH:
7.7 - 8.1
Dissolved oxygen:
8.5 - 9.0 mg/L
Nominal and measured concentrations:
Control and 100% saturated solution prepared at 100 mg/L (nominal, limit concentration)
1.0, 10% of the saturated solution (nominal, intermediate range-finding concentrations)
85 mg/L (48 h) and 89 mg/L (0 h) (measured in 100 mg/L solution)
Details on test conditions:
TEST SYSTEM
- Test vessel: 60 mL all-glass test vessels filled with 50 mL test medium
- Aeration: No aeration of test solutions
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2 (low concentrations: range-finding test) and 4 (limit concentration: limit test)
- No. of vessels per control (replicates):4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The test medium was prepared by adding analytical grade salts to tap water purified by Reverse Osmosis (RO-water, GEON Waterbehandeling, Berkel-Enschot, The Netherlands)
- Culture medium different from test medium: Culture medium: M7 (Elendt, 1990); Test medium: Tap water and salts
- Intervals of water quality measurement: pH and dissolved oxygen were measured at the beginning and at the end of the test, for the highest test concentration and the control. The temperature of the medium was measured continuously in a temperature control vessel.

OTHER TEST CONDITIONS
- Photoperiod: 16 h light, 8 h dark
- Feeding: No feeding during test

EFFECT PARAMETERS MEASURED:
- Immobilization (including mortality): After 24 and 48 h

RANGE-FINDING STUDY
- Test concentrations: A combined limit/range-finding test was performed with nominal concentrations of 1.0, 10 and 100% of saturated solution prepared at a loading rate of 100 mg/L
Reference substance (positive control):
yes
Remarks:
Potassium dichromate

Results and discussion

Effect concentrations
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: No
- Mortality of control: 0%


Results with reference substance (positive control):
- Results with reference substance valid? Yes, the effect values are within the historical ranges.
- EC50 (48 h) = 0.59 mg/L, 95% confidence interval: 0.53 - 0.72 mg/L
- Other: The reference test was performed on 02 - 04 Jul 2018 according to OECD guideline 202.
Reported statistics and error estimates:
No EC50 could be calculated because no effects were observed (EC50 > maximum concentration tested).

Any other information on results incl. tables

VALIDITY CRITERIA

The study fulfilled the criteria defined by the guideline (Table 1) and is thus considered valid and reliable.

Table 1: 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.

In the control, no daphnids were immobilized or showed no other signs of disease or stress.

Yes

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

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

Yes

 

ANALYTICAL RESULTS

The measured test item concentration in the undiluted saturated solution prepared at a nominal concentration of 100 mg/L was 89 mg/L at test start (0 h) and 85 mg/L at test end (48 h). Thus, the test item concentration was 96% of the initial concentration at test end (48 h) and thus remained stable for the duration of the test (Table 2). Therefore, it was concluded that the undissolved material removed during the preparation of the test samples was not test item related and the effect concentrations were based on the analytically confirmed nominal concentrations.

Table 2. Analytical results.

Sampling time

Percentage of saturated solution1

Analyzed concentration

Relative to initial

[h]

[%]

[mg/L]

[%]

0

0

100

n.d.

89.1

 

48

0

100

n.d.

85.2

n.a.

96

1                    Percentage of a saturated solution prepared at a loading rate of 100 mg/L

n.d.              not detected

n.a.               not applicable

 

BIOLOGICAL RESULTS

No immobility was observed in the control and at any of the test concentrations throughout the exposure period. The obtained effect values are summarized in Table 3.

Table 3. Summary of effect values.

Paramter

Nominal test item concentration [mg/L]

EC50 (24 h) and EC50 (48 h)

> 100

Applicant's summary and conclusion

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