Custom Red #2

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:

07-apr-2009 to 09-apr-2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): Custom Red #2
- Substance type: Violet powder
- Physical state: Solid
- Lot/batch No.: C50APR0805D
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark

Sampling and analysis

Analytical monitoring:

no

Details on sampling:

None performed

Test solutions

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Preparation of test solutions started with a loading rate of 100 mg/l applying 1 day of magnetic stirring to reach maximum solubility of the test substance in the test medium. The resulting aqueous mixture was filtered through a membrane filter (Whatman, 0.45 µm) where after the filtrate was used as the highest test concentration. Lower test concentrations were prepared by subsequent dilutions of the filtrate in test medium. The final test solutions were all clear and colourless.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Source: In-house laboratory culture
- Age at study initiation (mean and range, SD): < 24 hours
- Method of breeding: With newborn daphnids, i.e. less than 3 days old, by placing about 250 of them into 5 litres of medium in an all-glass culture vessel.
- Feeding during test: No

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/l expressed as CaCO3

Test temperature:

between 18.8 and 20.3°C

pH:

At t=0 h: 7.5
At t=48 h: 7.7 - 7.8

Dissolved oxygen:

At t=0 h: 8.5-9.1
At t=48 h: 9.0 - 9.1

Salinity:

Not applicable.

Nominal and measured concentrations:

Nominal concentrations: 0.10, 1.0, 10 and 100 mg/l

Measured concentrations: The study did not include sampling for determination of actual exposure concentrations because no analytical method could be validated to measure test concentrations due to the low solubility of Custom Red #2.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 ml, all glass
- Type (delete if not applicable): open - ~80 ml, normal headspace
- Aeration: no
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 for the highest concentration, 2 in the lower test concentrations
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Adjusted ISO medium
- Culture medium different from test medium: yes, for culturing M7 medium is used

OTHER TEST CONDITIONS
- Adjustment of pH: 7.7 ± 0.3
- Photoperiod: 16 hours photoperiod daily

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 daily


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 10
- Test concentrations: 0.10, 1.0, 10 and 100% of a filtered solution prepared at a loading rate of 100 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % of the filtrate

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: no
- Mortality of control: no
- Abnormal responses: not observed

Results with reference substance (positive control):

- Results with reference substance valid? yes

- EC50/LC50:
The 24h-EC50 was 0.55 mg/l with a 95% confidence interval between 0.50 and 0.63 mg/l.
The 48h-EC50 was 0.30 mg/l with a 95% confidence interval between 0.25 and 0.35 mg/l.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Due to the very low solubility of Custom Red #2 in test medium, concentration levels that might be toxic for daphnids could not be reached.

The 48h-EC50 was above a loading rate of 100 mg/l filtrate. Actual test concentrations could not be determined but were expected to be much lower.