Chromate(2-), [2,4-dihydro-4-[(2-hydroxy-4-nitrophenyl)azo]-5-methyl-2-phenyl-3H-pyrazol-3-onato(2-)][3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]-, disodium

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:

03 Jun 2014 - 31 Jul 2014

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

Principles of method if other than guideline:

None

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

None

Analytical monitoring:

yes

Details on sampling:

After sampling, the test medium samples (0.5 mL) were mixed with 0.5 mL methanol and stored deep-frozen (below -18 °C) until analysis.

Vehicle:

no

Details on test solutions:

The concentrations in the main test were spaced by a factor of 2.2. The necessary amount of FAT 20060/F for preparing the stock solution was weighed on weighing scoops and transferred to a volumetric flask. Test medium was added up to the benchmark and the solution was homogenised by shaking. The lower test solutions were prepared by dilution of the stock solution. Defined volumes of the prepared solution were transferred to each test vessels. The test solution volume was 50 mL per test vessel.

Test organisms (species):

Daphnia magna

Details on test organisms:

As test organism, Daphnia magna STRAUS, Clone V, was used. The animals are continuously bred in the laboratory and were originally purchased in a healthy condition from the Umweltbundesamt in Berlin/Germany. Daphnia magna was bred as single culture (one daphnid per 100 mL) in Elendt M4 medium. The pH-value of the aerated water was within a range of 6.0 – 9.0. The dissolved oxygen was above 60 % saturation and the total hardness 140 - 250 mg/L (as CaCO3), corresponding to 7.8 - 14 °dH. The animals were fed with single cell green algae (Desmodesmus subspicatus, former Scenedesmus subspicatus) at least three times a week.
The daphnids were reared at a temperature of 20 ± 2 °C in a climatic chamber with 16 h of illumination and 8 h of darkness. The medium was changed three times per week. A pipette was used to separate the young daphnids from the adults. Freshly hatched daphnids max. 24 hours old were used for the test.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

13° dH (232 mg/L as CaCO3)

Test temperature:

20.1 - 21.3 °C

pH:

7.95 - 8.08

Dissolved oxygen:

≥8.3 mg/L

Nominal and measured concentrations:

see Table below

Details on test conditions:

Test procedure: static
Duration: 48 hours
Temperature: 20.1 – 21.3 °C
Oxygen concentration: ≥8.3 mg/L
pH-value: 7.95 – 8.08
Exposure to light: 16 hours photoperiod / 8 hours darkness daily
Feeding: none
Test vessels: four 100 mL glass beakers per concentration, each filled with 50 mL
Loading: at least 10 mL of test solution for each animal Aeration: none
Number of animals: 20 per concentration in 4 replicates of 5

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

45.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

93.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % confidence limits: 86.3 - 101 mg/L

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

9.39 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

24.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % confidence limits: 15.9 - 36.6 mg/L

Details on results:

After 24 hours of exposure no immobilisation above the allowed control immobilisation was observed in the control and up to 45.5 mg/L. 70 % of the daphnids were found immobile at 100 mg/L.
After 48 hours of exposure no immobilisation above the allowed control immobilisation was observed in the control and up to 9.39 mg/L. 20 % of the daphnids were immobilised at 20.7 mg/L. At the two highest test item concentrations of 45.5 and 100 mg/L all daphnids were found immobile.

Results with reference substance (positive control):

EC50 (24 h) between 1.0 and 2.0 mg/L
Reference substance: potassium dichromate

Reported statistics and error estimates:

The 24 h and 48 h EC50 are the estimated concentrations where 50 % of the daphnids were immobilised after 24 and 48 hours, respectively. For the evaluation of the 24 h and 48 h EC50, logit analysis using linear max. likelihood regression was used. The evaluation of data was performed by using ToxRat Professional 2.10. The NOEC was established based on the highest concentration at which the immobilisation is not higher than the allowed control immobilisation (≤10 % immobilisation).

None

Validity criteria fulfilled:

yes

Conclusions:

The EC50 (48 h) for immobilisation was determined to be 24.1 mg test item/L (nominal). The corresponding NOEC (48 h) was 9.39 mg test item/L (nominal).

Executive summary:

FAT 20060/F was evaluated for short term toxicity to Daphnia magna in a study conducted according to OECD Guideline 202. The initial measured content of FAT 20060/F was 96 % of nominal, the arithmetic mean of fresh and aged samples was 95 % of nominal. Since the mean measured concentration of FAT 20060/F was between 80 – 120 %, the toxicological endpoints were evaluated using nominal concentrations of the test item.

ECx and NOEC -values of daphnids exposed to the test item evaluated using nominal concentrations:

Endpoint	FAT 20060/F [mg test item/L]
	24 h	48 h
NOEC	45.5	9.39
EC50	93.3	24.1
95 % confidence limit of EC50	86.3 - 101	15.9 – 36.6

 

The total hardness (as CaCO3) of the untreated control was determined to be 13 °dH (232 mg/L CaCO3).

The mean pH-value of the untreated control was determined to be 7.97 ± 0.02 (Std. Dev.).

The mean temperature of the control and all test item concentrations was measured to be 20.6 ± 0.4 °C (Std. Dev.).

The mean oxygen concentration was determined to be 8.6 ± 0.1 mg/L (Std. Dev.).

Description of key information

The EC50 (48 h) for immobilisation was determined to be 24.1 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

24.1 mg/L

Additional information

FAT 20060/F was evaluated for short term toxicity to Daphnia magna in a study conducted according to OECD Guideline 202. The initial measured content of FAT 20060/F was 96 % of nominal, the arithmetic mean of fresh and aged samples was 95 % of nominal. Since the mean measured concentration of FAT 20060/F was between 80 – 120 %, the toxicological endpoints were evaluated using nominal concentrations of the test item. ECx and NOEC-values of daphnids exposed to the test item evaluated using nominal concentrations:

Endpoint	FAT 20060/F [mg test item/L]
	24 h	48 h
NOEC	45.5	9.39
EC50	93.3	24.1
95 % confidence limit of EC50	86.3 - 101	15.9 – 36.6

 

The total hardness (as CaCO3) of the untreated control was determined to be 13 °dH (232 mg/L CaCO3). The mean pH-value of the untreated control was determined to be 7.97 ± 0.02 (Std. Dev.). The mean temperature of the control and all test item concentrations was measured to be 20.6 ± 0.4 °C (Std. Dev.). The mean oxygen concentration was determined to be 8.6 ± 0.1 mg/L (Std. Dev.).