Calcium 3-hydroxy-4-[(4-methyl-2-sulphonatophenyl)azo]-2-naphthoate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Each concentration was prepared separately. The stock solutions were stirred in M4 medium for about 20 hours at 20 ± 2 °C. Undissolved test substance was removed by centrifugation (approximately 20 min about 17700 G).

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: The clone of Daphnia magna STRAUS 1820 was supplied by the Institut National de Recherche Chimique Appliquée, France, in 1978. From this date on this cIone was cultured and bred continuously at the Laboratory of Ecology of BASF AG in Ludwigshafen.
- Age at study initiation: 2 - 24 h
- Feeding during test: no

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

2.42 mmol/L

Test temperature:

20.8 - 21.2 °C

pH:

7.9 - 8.1

Dissolved oxygen:

8.5 - 8.9 mg/L

Nominal and measured concentrations:

Nominal concentrations: control, 12.5, 25, 50, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Test tubes (glass) with flat bottom; nominal volume: 20 mL; fill volume: 10 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: A synthetic fresh water was used for culture and test purposes. This water was prepared on the basis of an ultrapure, demineralized water with a conductivity < 0 .05 µS/cm. For the composition of this M4 medium see IS0 10706.

OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: 16:8 h day-night regime
- Light intensity: ca. 2 - 7 µE/(m²s) at a wave length of 400 - 700 nm; Artificial light, type warm-.white (e .g. OSRAM L58 W31)

EFFECT PARAMETERS MEASURED:
- Check of the study and recording (swimming ability): visually after 0, 24 and 48 h
- Temperature: continuously during the whole test period in a separate vessel close to the test vessels
- pH and oxygen: After 0 h in an additional replicate without daphnids and after 48h in replicate 1 of each tested concentration

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: no effects observed up to the limit of water solubility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

50 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

The test was performed with an aqueous extract (eluate) of the test substance. At concentrations of 100 and 50 mg test substance/L (nominal) a red precipitation was observed.

Results with reference substance (positive control):

- The 24-h EC50 of the control substance potassium dichromate was 0.99 mg/L. [Date of the last control experiment: 09 Jan 2001, project-no: 97/0242/50/53]

Description of key information

With high probability acutely not harmful to aquatic invertebrates.

Additional information

One valid guideline study on the acute toxicity of the substance to Daphnia magna is available (BASF, 2001). The animals were exposed to the substance in a static test system. At test termination no effects were observed up to the limit of water solubility (at a nominal loading rate of 100 mg/L).