N-ethyl-N-[2-[1-(2-methylpropoxy)ethoxy]ethyl]-4-(phenylazo)aniline

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:

2.6.-4.6.2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study was carried out in accordance with internationally valid GLP principles.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: At the start of the exposure (0 h) samples from vessels without daphnids and at the end of the exposure (48 h) samples from vessels with daphnids were analyzed.
The transport to the analytical laboratory was done on the day of sampling.

- Sample storage conditions before analysis: All samples were stored at ambient temperature.

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
The substance has very low water solubility (<0.05 mg/L). Therefore the test solution was prepared according to OECD 23 by mixing 500.51 mg in 5L test medium (M4) and stirred for about 1 day. Undissolved test substance was removed with a membrane filter (pore width 0.2 micrometer).
The aqueous fraction of the test solution after separation of the undissolved material is a water accommodated fraction and is considered analogous to nominal concentration.
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain: STRAUS 1820
- Source: original clone obtained from Institut National de Recherche Chimique Appliquée, France in 1978. From this date on this clone was cultured and bred continuously in BASF SE ecotoxicology laboratory

- Age at study initiation (mean and range, SD): young daphnia <24 hours old
- Method of breeding: own laboratory breeding
- Feeding during test: none
- Acclimation conditions (same as test or not): same as test

CULTURE CONDITIONS
- Culture media: a synthetic fresh water (Elendt M4) as medium
- Type and amount of food: Unicellular algae Desmodesmus subspicatus cultured continuously at the test facility
- Feeding frequency: daily

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Post exposure observation period:

none

Hardness:

a synthetic fresh water (Elendt M4) as medium
total hardness 2.41 mmol•L-1

Test temperature:

20±1°C

pH:

8.1

Dissolved oxygen:

Has to be <3 mg/L , M4 medium is aerated for 24 hours prior to use
Test solution 0 mg/L: 8.7 mg/L (0 h, 48 h)
Test solution 100 mg/L: 7.1 mg/L (0 h) and 7.0 mg/L (48 h)

Nominal and measured concentrations:

nominal 100 mg (WAF), determined conc. < 0.05 mg/L (LoQ = 0.05 mg/L)

Details on test conditions:

TEST SYSTEM
- Type: open beaker (nominal volume 600 ml)
- Material, size, headspace, fill volume: glass, 400ml of the test solution in beaker
- Aeration: M4 medium is aerated for 24 hours prior to use
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Loading (biological): 0.013 animals/mL

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: a synthetic fresh water (Elendt M4) is used as media for culture and test purposes
- Particulate matter: no
- Acid capacity up to pH 4.3: 0.88 mmol•L-1
- Ca/Mg ratio: molar ratio Ca:Mg 4:1
- Conductivity: 597µS/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: At the beginning and the end of the test the ambient temperature, the oxygen content and pH value were measured.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light: 8 hours darkness
- Light intensity: 20-850 lux at a wave length of 400-750 nm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
The daphnia immobilisation was observed after 24 and 48 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: The concentrations for this study were selected in accordance with the requirements set forth in the test guidelines and based on the results of a preliminary finding test and main study was conducted as a limit test.
- Test concentrations: 0, 100 mg
- Results used to determine the conditions for the definitive study: in a preliminary test a concentration of 100 mg/L caused no immobilisation or symptoms after 48 hours.

Reference substance (positive control):

yes

Remarks:

(Potassium dichromate)

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 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

Results with reference substance (positive control):

- Results with reference substance valid? Yes. The result indicates that the culture of Daphnia magna used in this study is responding normally to toxic stress.
- EC50/LC50: 1.26 mg/L (24h)
- Other: tests with a ref. substance are conducted monthly acc. to OECD 202

Validity criteria fulfilled:

yes

Executive summary:

In conclusion the 48 hour EC₅₀values forSudan Marker 455 in this acute toxicity study with Daphnia magna was >100 mg/L based on nominalconcentration of the test substance.

 

The test substance is poorly soluble in water (water solubility estimated <0.05 mg/L). All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the guidance in OECD 23. The test substance had no observable acute effect onDaphnia magnaup to its saturation limit in test media and under test conditions.

 

The concentration of the test substance in test media was below the limit of quantification (0.05 mg/L) and could not be verified analytically. According to guidance in OECD 23, for tests with chemicals that cannot be quantified by analytical methods at the concentrations causing effects, the effect concentration can be expressed based on the nominal concentrations.

The results in this study are consistent with all validity criteria and the test is valid according to the guidelines of this study.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

In conclusion the 48 hour EC₅₀values forSudan Marker 455 in this acute toxicity study with Daphnia magna was >100 mg/L based on nominalconcentration of the test substance.

 The test substance is poorly soluble in water (water solubility estimated <0.05 mg/L). All reasonable efforts were taken to produce a saturated solution of the test substance in test media, following the guidance in OECD 23. The test substance had no observable acute effect onDaphnia magnaup to its saturation limit in test media and under test conditions.