Trisodium 3-[[4-[[6-(anilino)-1-hydroxy-3-sulphonato-2-naphthyl]azo]-5-methoxy-o-tolyl]azo]naphthalene-1,5-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:

06 February 2017 to 08 April 2017

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)

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: in the main test controls, 50 and 100% saturated solutions at 0 hour (bulk) and 48 hour (pooled from replicates) in duplicate
- Sample storage conditions before analysis:frozen

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION : in the range finding test undissolved substance was found at 1.0, 10 and 100 mg/L
A nominal amount of test item (1100 mg) was dispersed in 11 liters of test water with the aid of propeller stirring at approximately 1500 rpm for 24 hours. After 24 hours, the stirring was stopped and any undissolved test item was removed by filtration through a 0.2 µm Sartorius Sartopore filter (first approximate 2 liters discarded in order to pre-condition the filter) to give a 100% v/v saturated solution. A series of dilutions was made from this saturated solution to give further test concentrations of 6.25, 12.5, 25 and 50% v/v saturated solution. Each prepared concentration was inverted several times to ensure adequate mixing and
homogeneity.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: in-house laboratory culture
- Age : < 24 hours
- Feeding during test: none

ACCLIMATION
- Acclimation period: NA
- Culture conditions: temperature 18 to 22 °C; 16 hours light and 8 hours darkness cycle
with 20 minute dawn and dusk transition periods.:
- Type and amount of food: algal suspension (Desmodesmus subspicatus) and Tetramin
flake food suspensio
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

NA

Test temperature:

21-22 ºC

pH:

7.6-8.0

Dissolved oxygen:

8.6-8.8 mg/L (96-101% of saturation)

Salinity:

NA

Nominal and measured concentrations:

nominal: 0, 6.25, 12.5, 25, 50 and 100 % of saturation
measured at 0, 50 and 100% of saturation(at 0 and 48 h):

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 mL glass beakers with 100 mL test preparation
- Type): closed
- Aeration: no
- 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: fresh water (Elendt M7 medium according to the guideline pH 7.9, kept at 21 ºC)
- Adjustment of pH: no
- Photoperiod: 16 h light
- Light intensity: 634 to 675 Lux

EFFECT PARAMETERS MEASURED: immobility

RANGE-FINDING STUDY
- Test concentrations: 0, 0.1, 1, 10 and 100 mg/L (undissolved substance was present at 1.0, 10 and 100 mg/L)
- Results used to determine the conditions for the definitive study: immobilisation at 0, 0.1, 1, 10 and 100 mg/L : 0, 0, 0, 20 and 30% respectively

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 98 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

98 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: at this concentration 2/20 dapnids were immobilized

Details on results:

At 6.25% 1 daphnia in one replicate was found trapped at the surface
At the start and throughout the test, the control was observed to be a clear, colorless solution. The 6.25% v/v saturated solution test group was observed to be a clear, purple solution. The 12.5% v/v saturated solution test group was observed to be a clear, dark purple solution. The 25, 50 and 100% v/v saturated solution test groups were observed to be opaque, purple solutions.

Results with reference substance (positive control):

potassium dichromate EC50 (48 h) 1.2 mg/L

Reported statistics and error estimates:

Fisher’s Exact Binomial Test with Bonferroni correction

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 for daphnia magna is >98 mg/L

Executive summary:

In a static test according to OECD 202 20 daphnids/concentration were exposed to 0, 6.25, 12.5, 25, 50 and 100 % of a saturated solution in Elendt M7 medium. Measured concentrations at 0, 50 and 100% were at 0 and 48 h: <LOQ and < LOQ, 48.7 and 48.9 mg/L  and 98.3 and 99.2 mg/L. At 100% 2/20 daphnids were found immobilised at the 48 hour observation. As this finding is within the criteria for a valid control, the NOEC is set at 98 mg/L (initial concentration). The 48 h EC50 for daphnia magna is >98 mg/L.

Description of key information

In a static test according to OECD 202 20 daphnids/concentration were exposed to 0, 6.25, 12.5, 25, 50 and 100 % of a saturated solution in Elendt M7 medium. Measured concentrations at 0, 50 and 100% were at 0 and 48 h: <LOQ and < LOQ, 48.7 and 48.9 mg/L  and 98.3 and 99.2 mg/L. At 100% 2/20 daphnids were found immobilised at the 48 hour observation. As this finding is within the criteria for a valid control, the NOEC is set at 98 mg/L (initial concentration). The 48 h EC50 for daphnia magna is >98 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

98 mg/L