isliFe

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

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)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Batch number : TROD7BB06

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

The primary stock solution used in the range-finding test was prepared by dissolving 10 mg of the test substance in 40 mL of dilution water (M4 medium) and the total volume was completed to 100 mL, resulting in a concentration of 100 mg.L. The secondary stock solutions were prepared by dilutions of the primary stock solution.

The primary stock solution used in the definitive test was prepared by dissolving 20 mg of the test substance in 40 mL of dilution water (M4 medium) and the total volume was completed to 200 mL, resulting in a concentration of 100 mg.L-1.

Test organisms (species):

Daphnia magna

Details on test organisms:

Young Daphnia magna 24 hours old were obtained from the culture kept at the Ecotoxicology Laboratory, maintenance and cultivation records are archived at BIOAGRI.
The test system Daphnia magna was obtained from the CAROLINA BIOLOGICAL SUPPLY COMPANY - Burlington, North Carolina (USA) and maintained as a stock culture at BIOAGRI.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

178.2 mg/L

Test temperature:

20.1-20.3°C

pH:

7.7-8.2

Dissolved oxygen:

7.8-8.1 mg/L

Conductivity:

450 µS/cm

Nominal and measured concentrations:

nominal: 100 mg/L

Details on test conditions:

In the range-finding test the exposure conditions were:
a) Total number of organisms per each tested concentration or control: 10;
b) Number of replicates per each tested concentration and control: 2;
c) Number of organisms per test container: 5;
d) Volume: 15 mL of test solution per test container, 3 mL to each Daphnia;
e) The organisms were distributed randomly in the test container. Firstly, three organisms were
placed in each test container and, finally, two organisms were added to the container;
f) Nominal used concentrations: control; 0.01; 0.1; 1; 10 and 100 mg.L-1;
g) Temperature of the test solutions: 20.1 to 20.2°C;
h) Photoperiod: 16 hours of light and 8 hours of dark;
i) Parameters evaluated: immobility after 24 and 48 hours; and still animals were considered
unable to swim for a period of 15 seconds of observation after mild agitation of the flasks.

In the definitive test the exposure conditions were:
a) Total number of organisms per each tested concentration or control: 20;
b) Number of replicates per each tested concentration and control: 4;
c) Number of organisms per test container: 5;
d) Volume: 15 mL of test solution per test container, 3 mL to each Daphnia;
e) The organisms were distributed randomly in the test container. Firstly, three organisms were
placed in each test container and, finally, two organisms were added to the container;
f) Nominal used concentrations: control and 100 mg.L;
g) Temperature of the test solutions: 20.1 to 20.3°C;
h) Photoperiod: 16 hours light and 8 hours dark;
i) Parameters evaluated: immobility after 24 and 48 hours; and still animals were considered
unable to swim for a period of 15 seconds of observation after mild agitation of the flasks;
j) Analytical determination: content dissolved oxygen, pH of the test solutions and the test
substance concentration were determined at the beginning of the test and after 48 hours.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

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

Results with reference substance (positive control):

The 24-hours EC50 value of the reference substance (potassium dichromate) was 1.06 mg.L-1 (95% confidence limits = 0.91 to 1.22 mg.L-1), showing the sensitivity of the test system (ISO 6341 / OECD 202, 2004).

Validity criteria fulfilled:

yes

Conclusions:

The 48-hours EC50 value was not determined because the highest tested concentration of MEAHA-Fe, 100 mg/L, did not cause immobility to the test organisms. Therefore the 48-hours EC50 value of the tested substance is higher than 100 mg/L.

Executive summary:

This study was carried out in order to evaluate the acute toxicity of MEAHA-Fe to Daphnia magna.

A range-finding test was carried out to determine the concentrations that caused 100% and 0% of acute toxic effect. According to the results obtained in the range-finding test, a definitive test was carried out with only the maximum concentration of 100 mg.L-1. A control was also added. Twenty organisms were used per concentration and control distributed into four replicates. The definitive test was conducted in a controlled environment with temperature ranging from 20.1 to 20.2°C for 48 hours with photoperiod of 16 hours light and 8 hours of dark. The 48-hours EC50 value was not determined because the highest tested concentration of MEAHA-Fe, 100 mg.L-1, did not cause immobility to the test organisms. Therefore the EC50 value of the tested substance is higher than 100 mg.L-1. The statistical method used was Trimmed Spearman-Karber.

Description of key information

The 48-hours EC50 value was not determined because the highest tested concentration of MEAHA-Fe, 100 mg/L, did not cause immobility to the test organisms. Therefore the 48-hours EC50 value of the tested substance is higher than 100 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L