Calcium 4-[(5-chloro-4-methyl-2-sulphonatophenyl)azo]-3-hydroxy-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:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes

Specific details on test material used for the study:

- Storage condition of test material: At room temperature at about 20 °C, away from direct sunlight

Analytical monitoring:

yes

Details on sampling:

For the determination of the actual test item concentration, duplicate samples were taken from each treatment before the start and at the end of the test. For the 48-hour stability samples additional flasks with adequate volumes of the freshly prepared test medium and the control were incubated during the test period imder the same conditions as in the actual test (but without daphnids). Sampling from the test beakers with daphnids was not possible because the test medium volume per beaker (50 mL) was too small for the analytical requirements (500 mL per sample). All samples were stored deep-frozen (at about -20 °C) immediately after sampling. Based on preexperiments for investigation of the storage stability (without GLP), the analyzed main component of the test item was found to be sufficiently stable in the test water under these storage conditions. The concenfration of the main component of the test item was analytically measured in the duplicate test medium samples of the single test concenfration taken at the start and the end of the test. From the control, only one of the duplicate samples was analyzed from each of the sampling times.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Due to the limited water solubility of the product, containing sparingly soluble components, a water accommodated fraction (WAF) was prepared according to OECD guidence document No. 23. A dispersion of 100 mg/L was prepared by dispersing 250.4 mg of the test item into 2500 ml of test water. The dispersion was stirred in the dark for 3 hours. After the stirring period of 3 hours, the dispersion was filtered through a membrane filter

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Strain: clone 5
- Source: Originally supplied by the University of Sheffield, UK in 1992. Since that time, the clone has been bred in the laboratories of RCC.
- Age at study initiation: 6 - 24 hours
- Feeding during test; none
- Housing conditions: same as test

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mmol/L

Test temperature:

20 °C

pH:

7.8

Dissolved oxygen:

8.0 - 8.6 mg/L

Nominal and measured concentrations:

- Nominal test concentrations: control, 100 mg/L
- Mean measured concentrations: not applicable, 0.0086 mg/L

Details on test conditions:

TEST SYSTEM
- Material, nominal volume, fill volume: glass beakers, 100 mL, 50 mL
- No. of organisms per vessel: 5
- No. of vessels per concentration: 4
- No. of vessels per control: 4
- Biomass loading rate: 0.5 daphnia/ mL

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water aerated prior to the test strat until oxygen saturation was reached
- Alkalinity: 0.8 mmol/L
- Ca/Mg ratio: 4:1
- Culture medium different from test medium: no
- Intervals of water quality measurement: Temperature, pH, oxygen content after 0 and 48 hours

OTHER TEST CONDITIONS
- Photoperiod: 16 hour light : 8 hour darkness (30 min transition period)
- Light intensity: 490 to 640 lux

EFFECT PARAMETERS MEASURED: immobility after 24, 48 hours

Reference substance (positive control):

yes

Remarks:

potassium dichromate

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:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: none
- Mortality of control: none
- Apperance of the test medium: no remarkable observations, clear test medium

Results with reference substance (positive control):

48h-EC50 = 0.73 mg/L (control test in Dec 2006)

Validity criteria fulfilled:

yes

Conclusions:

With high probability acutely not toxic to aquatic invertebrates.

Description of key information

With high probability acutely not toxic to aquatic invertebrates.

Additional information

In a guideline study following OECD 202 the acute toxicity of the substance to Daphnia magna was tested (RCC Ltd, 2007). The exposure was conducted in a static system. Based on the mobility of the animals after 48 hours of exposure no effects were observed up to the limit of water solubility (at a nominal loading rate of 100 mg/l).