Chromate(2-), [2,4-dihydro-4-[(2-hydroxy-5-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:

1996

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

Specific details on test material used for the study:

Code number: FAT20010/C
Batch no: 149
Purity: ca. 70 %
Appearance: solid
Solubility: >1 g/I miscible [in water]
Storage: room temperature
Expiration date: 12/1999

Analytical monitoring:

yes

Vehicle:

no

Details on test solutions:

Stock solution
110 mg test substance were mixed with 200 ml test medium in a beaker and then filled up to 500 ml with test medium.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Method of breeding: Cultures of Daphnia magna are held in glass vessels containing approx. 3.0 litre of reconstituted water at 18 - 22 °C. The water is renewed partially three times per week. The Daphnia are fed with a suspension of green algae (Scenedesmus subspicatus) supplemented by a Tetramin-extract in such quantities that the food will be consumed within 24 hours

Pretreatment:
- 24 hours before the start of the exposure reproductive Daphnia were separated from the young Daphnia by sieving all individuals through a 1000 μm sieve.
For each test concentration 20 Daphnia divided in two groups of 10 animals were used.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

231 mg/L CaCO3

Test temperature:

18-22 °C (during the test max. ± 1 °C),

pH:

7.6 - 8.0

Nominal and measured concentrations:

Due to the results of a pretest the nominal test concentrations were chosen as 0.9, 1.9, 4.3, 9.4, 21, 45 and 100 mg test article/L. All test concentrations contained the vehicle Tween 80 (Polyoxyethylensorbitan-monooleat) in a concentration of 5 ppm. The test concentrations of 0.9, 1.9 and 4.3 mg/I were below the NOEC. Therefore, the data of these concentrations were not used for the determination of the EC values and were not presented in the report, but are documented in the raw data of the study.

Details on test conditions:

Experimental conditions
48 hours at nominal 18-22 °C (during the test max. ± 1°C), 12 hours light 12 hours dark. The Daphnia were exposed to the test substance in 250 ml beakers containing 80-100 ml test medium with 10 animals per beaker. All tests are running in duplicate.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

7.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

31 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

78 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

7.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

No significant immobilization and abnormal behaviour of the Daphnia was observed in the controls. In the vehicle control one Daphnia was immobilized after 48 hours. This effect was inside the range of 10 % required by the guidelines for the validity of the test. In the test concentration of 7.9 mg/I (nominal 9.4 mg/I) no immobilization of the Daphnia occurred. Therefore, the NOEC and EC0 value after 48 hours was determined to be 7.9 mg/L.

Results with reference substance (positive control):

48h EC50 = 0.93 mg/I.

Validity criteria fulfilled:

yes

Conclusions:

The EC50 values after 48 hours was calculated as 31 mg/I.

Executive summary:

A test was conducted to determing the acute fish toxicity of FAT 20010/C to Daphnia magna was carried out to determine the EC50 (concentration at which 50 % of the Daphnia population is immobilized) according to OECD guideline 202 in compliance with GLP. 10 Daphnids each were exposed to concentration of 9.4, 21, 45 and 100 mg/L. During the test the actual test concentrations in the analysed test media were in the range of 77.6 - 85.1 % of the nominal values. No significant immobilization and abnormal behaviour of the daphnids was observed in the controls. In the test concentration of 7.9 mg/I (nominal 9.4 mg/I) no immobilization of the daphnids occurred. Therefore, the NOEC and EC0 value after 48 hours was determined to be 7.9 mg/I. The EC50 values after 48 hours was calculated to be 31 mg/L.

Description of key information

48 h EC50 value of FAT 20010/C to Daphnia magna was calculated to be 31 mg/L. The NOEC and EC0 value after 48 hours was determined to be 7.9 mg/I.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

31 mg/L

Additional information

A GLP-compliant test was performed to assess the toxicity of test substance FAT 20010/C to Daphnia magna according to OECD guideline 202. At the end of 48 h exposure period the EC50 value of FAT 20010/C to Daphnia magna was calculated to be 31 mg/L. The NOEC and EC0 value after 48 hours was determined to be 7.9 mg/I.