Sodium 4-[[4-[(4-hydroxy-2-methylphenyl)azo]phenyl]amino]-3-nitrobenzenesulphonate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 - 29 Nov 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

analytical verification lacking for two lower test concentrations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1997

Report date:

1997

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

at the time being tested, the guideline did not mention 5 concentrations to be used, so only 4 concentrations were used here

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 4-[[4-[(4-hydroxy-2-methylphenyl)azo]phenyl]amino]-3-nitrobenzenesulphonate

EC Number:

274-950-1

EC Name:

Sodium 4-[[4-[(4-hydroxy-2-methylphenyl)azo]phenyl]amino]-3-nitrobenzenesulphonate

Cas Number:

70865-20-2

Molecular formula:

C19H16N4O6S.Na

IUPAC Name:

sodium 4-[[4-[(4-hydroxy-2-methylphenyl)azo]phenyl]amino]-3-nitrobenzenesulphonate

Test material form:

solid: particulate/powder

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: all
- Sampling method: taken from approximate centre of test vessel
- Sample storage conditions before analysis: kept at -18°C to -25°C until analysis

Test solutions

Vehicle:

no

Details on test solutions:

100.2 mg test item were mixed with 200 mL test medium, homogenised by ultrasonic treatment for 15 min and filled up to 1000 mL with test medium. Due to limited solubility of the test item, the test item was not completely soluble. For the preparation of the test concentrations, only the supernatant of the stock solution was used.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: own breed
- Feeding during test: no
- Food type: suspension of green algae and Tetramin extract
- Amount: amount needed for 24 h
- Frequency: daily

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

280 mg/L CaCO3 (test medium)

Test temperature:

20°C

pH:

7.7

Dissolved oxygen:

98% saturation

Nominal and measured concentrations:

Nominal: 0 (control), 9.4, 21, 45, 100 mg/L
Measured (arithmetic mean):

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beaker
- Material, size, headspace, fill volume: 250 mL, fill volume: 60-100 mL
- Aeration: no
- No. of organisms per vessel: 1ß
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Aqua bidist.
- Alkalinity: 0.8 mmol/L
- Ca/mg ratio: 4:1
- Culture medium different from test medium: no
- Intervals of water quality measurement: beginning of each test

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 12/12 h

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility (24, 48h)


RANGE-FINDING STUDY
- Test concentrations: 0.01 - 100 mg/L
- Results used to determine the conditions for the definitive study: yes

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

42 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Mortality of control: no

Results with reference substance (positive control):

24-h EC50: 0.9 mg/L corresponding to a normal sensitivity (24 Oct 1996)

Reported statistics and error estimates:

Probit model

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48-h EC50 to Daphnia magna was determined at 42 mg/L based on mean measured concentrations.