Tetrasodium 2-[[4-[[4-[[1-hydroxy-6-(phenylamino)-3-sulphonato-2-naphthyl]azo]-1-naphthyl]azo]-6-sulphonato-1-naphthyl]azo]benzene-1,4-disulphonate

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:

24.04.-29.04.2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

yes

Remarks:

The analytical determination of the test substance concentrations were performed at the beginning of test, before renewal of the test solutions, after renewal of the test solutions and at the end of the preliminary semi-static test.

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Preparation of Sample Solutions: The samples of test solutions were prepared and delivered by Ecotoxicity group. The samples were analyzed on the day of delivery. The samples were analysed non-diluted.

Details on test solutions:

The stock solution of the test substance was prepared in the dilution water. 100 mg of the test substance was weighed into 1000 mL of the dilution water for the preliminary and definitive test. Because the test substance was poorly soluble for dilution was used ultrasound for 1 hours and stirring for 2 hours. The concentrations of solutions used in the preliminary and definitive test were obtained by dilution of the stock solution with dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM- Common name: Daphnia magna- Strain: Straus- Source: own laboratory breeding.- Age at study initiation: young Daphnia born in 24h- Method of breeding: aperiodic parthenogenesis - Feeding during test: noACCLIMATION- Acclimation period: 48h- Acclimation conditions: same as test- Type and amount of food: a mixture of algae- Health during acclimation: mortality control, healthy

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Ca+Mg ions2.52-2.53 mmol/L preliminary study

Test temperature:

20±2°C

pH:

7.8

Dissolved oxygen:

>3 mg/L

Nominal and measured concentrations:

100, 50, 10, 5, 1 mg/L preliminary test

Details on test conditions:

TEST SYSTEM- Test vessel: glass beakers, 50 ml- Type: open- Aeration: withoutNumber of test animals: 20 for each concentration and control Number of replicates (per concentration): 2Number of test animals per replicate: 10Volume of test substance solution: 50 mL per 10 individualsDilution water was prepared just before the test by admixing 2.5 mL of stored solutions A, B, C and D into 1000 mL of deionized water.A.117.6 g CaCl2.2H20 in 1 L of deionized waterB.49.3 g MgSO4.7H2O in 1 L of deionized waterC.25.9 g NaHCO3 in 1 L of deionized waterD.2.3g KCl in 1 L of deionized water

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 31.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 31.7 mg/L

Nominal / measured:

meas. (TWA)

Conc. based on:

test mat.

Basis for effect:

mobility

Results with reference substance (positive control):

Reference testThe sensitivity of the test species and correctness of test performance is periodically verifiedin six-month period by testing with the reference substance, potassium dichromate.The results of the verification test with K2Cr2O7, carried out in period from 15.04. to 17.04.2015 are the following:24 hour – EC50 = 1.95 mg.L-1(95% confidence limit: 1.75 – 2.15 mg.L-1)48 hour – EC50 = 0.86 mg.L-1(95% confidence limit: 0.70 – 1.02 mg.L-1)

Validity criteria fulfilled:

yes

Conclusions:

The experiment with the concentration of 100 mg.L-1 included in the preliminary semi-static test has been performed using 20 daphnia, therethrough the conditions of the limit test given in guidelines have been fulfilled. It was demonstrated that the EC50 is higher then this concentration.

Executive summary:

The test substance, Direct Blue 78, was tested in acute immobilisation test on Daphnia magna.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test,Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

 

The preliminary test was performed in range of the test substance nominal concentrations
1 – 100 mg·L^-1.

The test was performed as semi-static.The test solutions were renewed after 24 hours.
The test substance concentrations was measured at the beginning, after 24 hours (before and after renewal) and at the end of the test at the highest (100 mg·L^-1) and the lowest concentration (1 mg·L^-1).

The analytical results from the preliminary semi-static test showed, that the test substance was not stable in dilution water at conditions of the test.

Based on no toxicity of the test substance found in preliminary semi-static test, the study was terminated.The experiment with the nominal concentration of 100 mg·L^-1included in the preliminary semi-static test has been performed using 20 daphnia, therethrough the conditions of the limit testgiven in guidelinehave been fulfilled. It was demonstrated that the EC₅₀is higher than this concentration.

There is stated in the guideline that, if evidence is available to demonstrate that the concentration of the test substance has been satisfactorily maintained within ± 20 percent of the nominal or measured initial concentration throughout the test, the results can be based on nominal or measured initial values.

Because concentrations of the test substance have not been satisfactorily maintained
within ± 20 percent of the nominal or measured initial concentration throughout the test, time-weighted mean concentrations were used for evaluations and results.

 

 

Test results:

24 hour–EC₅₀>31.7 mg·L^-1                              (time-weighted mean concentration)

48 hour–EC₅₀>31.7 mg·L^-1                              (time-weighted mean concentration)

 

24 hour–EC₀= 31.7mg·L^-1               (time-weighted mean concentration)

48 hour–EC₀= 31.7mg·L^-1               (time-weighted mean concentration)

 

24 hour–EC₁₀₀>31.7 mg·L^-1             (time-weighted mean concentration)

48 hour–EC₁₀₀>31.7 mg·L^-1            (time-weighted mean concentration)

Description of key information

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test,Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

Only one study is available.

GLP study.

Klimish score 1.

(48h) EC50>31.7 mg/L

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

31.7 mg/L