Disodium 4,4'-bis(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-ylazo)-1,1'-biphenyl-2,6'-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:

From April 21 to 23, 1998

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)

Version / remarks:

1992

GLP compliance:

yes

Analytical monitoring:

yes

Details on test solutions:

Preparation of the stock solution and dilution
The test substance was stirred in M4 medium for about 20 hours at appr. 20 ± 2 °C. Undissolved test substance was removed by means of centrifugation (appr. 20 minutes at about 17700 G). The nominal concentration of the eluate was 100 mg/l.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna STRAUS 1820
- Source: Institut National de Recherche Chimique AppIiquée, France
- Age of parental stock (mean and range, SD): 2 - 4 weeks
- Age of the animais at the start of the test 2 - 24 hours (starting with the 3. instar)
- Feeding during test: none

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2,20 - 3,20 mmol/l

Test temperature:

18 - 22 °C (max. temperature difference 2 °C)

pH:

7.5 - 8.5

Conductivity:

550 - 650 µS/cm

Nominal and measured concentrations:

12.5, 25, 50, 100 mg/l nominal concentration

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes with fiat bottom
- Type (delete if not applicable): open / closed
- Material, size, headspace, fill volume: glass, nominal volume 20 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: water is prepared an the basis of an ultrapure, demineralized water with a conductivity < 0.05 µS/cm.
- Alkalinity: up to pH 4.3, 0,80 - 1,00 mmol/l
- Ca/mg ratio: about 4: 1
- Conductivity: 550 - 650 pS/cm

OTHER TEST CONDITIONS
- Photoperiod: Artificial Iight, type warm white (eg. OSRAM L58 W31) day : night-rhythm = 16 : 8 hours
- Light intensity: About 2 - 7 µE/(m2S) in the wave Iength of 400 - 700 nm

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 39.4 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 39.4 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 39.4 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

39.4 mg/l measured concentration corresponding to 100 mg/l of nominal concentration.

Validity criteria:

- In the control the immobilization was ≤ 10%.

- In the controi no Daphnids were captured in a surface film.

- The O2-concentration was in all tested replicates > 3 mg/l.

- The EC50 (24h) of the control substance potassium dichromate was 1,29 mg/L. (Date of the last control experiment: 17.03.98)

Validity criteria fulfilled:

yes

Conclusions:

EC50 (48h) > 39.4 mg/l ( >100 mg/l nominal)

Executive summary:

Method

The acute toxicity of the test substance to Daphnia magna STRAUS was investigated in a 48-hour static test according to EEC Directive 92/32/EEC (December 1992). The test substance was tested in the range of concentrations between 12.5 mg/l and 100 mg/l. The dilution factor was 2.

lnstead of mortality the test criterion of the acute toxicity is immobilization of the daphnids after 48 hours of exposure which is expressed as EC (effect concentration). Those animals were considered to be immobile which were unable to swim within 15 seconds even after gentle agitation of the test vessel.

Results

EC50 (48h) > 39.4 mg/l ( >100 mg/l nominal )

Description of key information

EC50 (48h) > 39.4 mg/l ( >100 mg/l nominal)

Additional information

The acute toxicity of the test substance to the water flea Daphnia magna STRAUS was investigated in a 48-hour static test according to EEC Directive 92/32/EEC (December 1992). The test substance was tested in the range of concentrations between 12,5 mg/l and 100 mg/l. The dilution factor was 2.

lnstead of mortality the test criterion of the acute toxicity is immobilization of the daphnids after 48 hours of exposure which is expressed as EC (effect concentration). Those animals were considered to be immobile which were unable to swim within 15 seconds even after gentle agitation of the test vessel.

EC50 (48h) > 39.4 mg/l ( >100 mg/l nominal)