[No public or meaningful name is available]

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 24 March to 20 August 2021

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

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch/Lot number: 465884
Description: White to off-white to slightly yellow solid
Purity: 100%

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 100 mg/L
- Sampling method: samples were taken and analyzed at the beginning and at the end of the renewal periods.
- Sample storage conditions before analysis: below -15°C

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution with a nominal concentration of 100.0 mg/L (nominal) was prepared with direct addition of the test item and mixed into the test medium (ISO Medium).
The test solution was prepared just before introduction of the Daphnia (start of the renewal periods).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Age at study initiation (mean and range, SD): Less than 24 h old at the beginning of the test
- Source: Hungarian University of Agriculture and Life Sciences, Department of Aquaculture 2100 Gödöllő, Páter Károly u. 1. – Hungary
- Feeding during test
The Daphnia were fed with concentrated algal suspension of Raphidocelis subcapitata during the holding and were not fed during the test.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

225 mg/L (as CaCO3)

Test temperature:

19.9 °C - 20.4°C

pH:

7.76–7.96

Dissolved oxygen:

7.0 – 8.4 mg/L

Nominal and measured concentrations:

Nominal 100 mg/L; Measured concentration (

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Volume of solution: at least 5 mL test solution/animal
- Renewal rate of test solution (frequency/flow rate): 24 hours
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: The test was carried out in 16-hour light and 8-hour dark cycle.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Observation of environmental parameters
The water temperature was determined daily in one control test vessel and continuously with a min/max thermometer in the climate chamber.
The oxygen concentration and pH were measured in both the control and the test concentration level (in one test vessel) at the start and at the end of the renewal periods.
Observation of animals
The number of mobile and immobilized test animals was observed and recorded 24 and 48 hours after the start of the test. Those animals not able to swim within 15 seconds after gentle agitation of the test beaker were considered to be immobile.

RANGE-FINDING STUDY
- Test concentrations: 0.1, 1, 10, 100 mg/L
- Results used to determine the conditions for the definitive study: Because no significant inhibition was observed during the preliminary range-finding test, a Limit test was carried out using only one test concentration at 100.0 mg/L and one control group in a semi-static main test.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

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:

The number of immobilised animals and the percentage of immobility were determined at the 24th and 48th hour in the definitive experiment.
In addition to immobility, no abnormal behaviour or appearance of test animals was detected.

Results with reference substance (positive control):

The 24h EC50: 0.73 mg/L, (95 % confidence limits: 0.69 – 0.78 mg/L)
This result falls within the acceptable range (0.6 mg/L to 2.1 mg/L) hence this reference study shows that the acute immobilization test on Daphnia magna is valid in this laboratory.

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 of test item to Daphnia magna is determined as > 100 mg/L.

Executive summary:

Acute toxicity of test item was assessed with Acute immobilisation test on Daphnia magna, over an exposure period of 48 hours in a semi-static system.
Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of test item were the following: 24h and 48 h EC50 >100 mg/L, 48h NOEC =100 mg/L.

Description of key information

Acute toxicity of test item was assessed with Acute immobilisation test on Daphnia magna, over an exposure period of 48 hours in a semi-static system.
Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of test item were the following: 24h and 48 h EC50 >100 mg/L, 48h NOEC =100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Dose descriptor:

EC50

Effect concentration:

> 100 mg/L