2-ethylanthraquinone

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from November 1990 to 23 September 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline-conform study performed under GLP

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 0 (DMSO control), 250 and 500 µg/L (nominal)
- Sampling method: not reported
- Sample storage conditions before analysis: stored cool and dark

Vehicle:

yes

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: A stock solution of 2-ethylanthraquinone was prepared as follows: 50 mg 2-ethylanthraquinone was dissolved in 10 mL DMSO to obtain a concentration of 5000 mg/L. This stock solution was diluted with DMSO to obtain a second stock solution of 2500 mg/L. To erlenmeyers of 5
liter, wrapped in aluminium foil and containing 4 litre ISO-water, 400 µL of these stock solution were added. These solutions were stirred for 2 hours to obtain homogeneous nominal test concentrations of 500 and 250 µg/L. The ISO-water was prepared and aerated at least 24 hours prior to the test.
- Eluate: not applicable
- Differential loading: not reported
- Controls: A control with DMSO in ISO-water (0.1 ml/l) and a control with ISO-water were included in the test.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): DMSO
- Evidence of undissolved material (e.g. precipitate, surface film, etc): No

Test organisms (species):

Poecilia reticulata

Details on test organisms:

TEST ORGANISM
- Common name: Guppy
- Strain: not reported
- Source: RASBORA, Veenendaal, The Netherlands
- Age at study initiation (mean and range, SD): not reported
- Length at study initiation (length definition, mean, range and SD): 1.7-3.0 cm
- Weight at study initiation (mean and range, SD): 0.45 g (mean)
- Method of breeding: not reported
- Feeding during test: The fish were not fed during the test.

ACCLIMATION
- Acclimation period: 13 March 1991 - 22 April 1991
- Acclimation conditions (same as test or not): no (different light conditions)
- Type and amount of food: troutfeed
- Feeding frequency: daily
- Health during acclimation (any mortality observed): not reported

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

reconstituted dilution water: 250 mg/L

Test temperature:

22.4 - 26.4 °C, see table in "Any other information on materials and methods incl. tables" for details

pH:

7.4 - 7.9, see table in "Any other information on materials and methods incl. tables" for details

Dissolved oxygen:

8.4-9.4 mg/L, see table in "Any other information on materials and methods incl. tables" for details

Nominal and measured concentrations:

nominal: 0 µg/L (control), 0 µg/L (DMSO-control), 250 µg/L, 500 µg/L
mean measured test concentrations based on all measured data (before and after renewal):
control: DMSO control: nominal 250 µg/L: 190 µg/L (Vessel 1), 187 µg/L (Vessel 2)
nominal 500 µg/L: 373 (Vessel 1), 365 (Vessel 2)

Details on test conditions:

TEST SYSTEM
- Test vessel: not reported
- Type (delete if not applicable): not reported
- Material, size, headspace, fill volume: not reported
- Aeration: not reported
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): renewed each 24 hours after test initiation
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: not reported

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: not reported
- Composition of reconstituted dilution water:
Deionised water
CaCl2 · 2 H2O: 294 mg/L
MgSO4 · 7H2O: 123 mg/L
NaHCO3: 64 mg/L
KCl: 5.8 mg/L
- Culture medium different from test medium: no
- Intervals of water quality measurement: not reported

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod:
- Light intensity: less than 100 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : After 24,48, 72 and 96 hours mortality of the fish was recorded. After 96 hours the following abnormalities were recorded as well: hyperactivity, hypoactivity, hyperventilation, uncontrolled movement, loss of equilibrium and discolouring.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Justification for using less concentrations than requested by guideline: Because no mortality occurred in the range finding studies, the final test was carried out at 2 concentrations, one slightly above and one slightly below the water solubility level.
- Range finding study: yes
- Test concentrations: various
- Results used to determine the conditions for the definitive study: No mortality occurred at the nominal test concentrations of 500 µg/L. Therefore, the final test was carried out at 2 concentrations, one slightly above and one slightly below the water solubility level.

Reference substance (positive control):

yes

Remarks:

potassium bichromate (once a year, last test: November 1990)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 370 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

370 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: none reported
- Observations on body length and weight: not reported
- Other biological observations: none reported
- Mortality of control: 1/20 72 hours after initiation of test
- Other adverse effects control: the fish that died was in bad condition 48 hours after initiation of test
- Abnormal responses: none reported
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: LC50 and NOEC values are both above the solubility limit.

Results with reference substance (positive control):

LC50.96h: 120 mg/L
95% confidence interval: 90-160 mg/L

Sublethal observations / clinical signs:

Mortality of guppies during the acute toxicity test

Mean measured concentration (µg/L)	Number of dead guppies per test vessel				Total number of dead guppies	Number of guppies tested	Mortality (%) at 96 hours
	24h	48h	72 h	96 h
0 (control)	0	0*	1	0	1	5	1
0 (control)	0	0	0	0	0	5
0 (DMSO-control)	0	0	0	0	0	5	0
0 (DMSO-control)	0	0	0	0	0	5
190	0	0	0	0	0	5	0
187	0	0	0	0	0	5
373	0	0	0	0	0	5	0
365	0	0	0	0	0	5

*one fish in bad condition

Validity criteria fulfilled:

yes

Conclusions:

Based on the mean measured test concentrations the LC50.96 h was higher than 370 µg/L and the NOEC - no observed effect concentration - was 370 µg/L, which means that both figures are above the water solubility level.

Executive summary:

The acute toxicity of 2-ethylanthraquinone to guppies (Poecilia reticulafa, Poeciliidae) was tested according to OECD TG 203 at nominal test concentrations of 250 and 500 µg /L in ISO-water (solubility limit 254 µg/L). As 2-ethylanthraquinone is highly unstable in water under influence of light, the test was conducted under reduced light conditions (<100 lux) to reduce the decrease in test concentration. In addition, each 24 hours the test solutions were renewed. Samples of the test concentrations were taken 0, 24, 48, 72 and 96 hours after test initiation, before and after renewal of the test solutions, and analysed with HPLC. Based on the mean measured test concentrations the LC50.96 h was higher than 370 µg/L and the NOEC - no observed effect concentration - was 370 µg/L, which means that both figures are above the water solubility level.

Description of key information

In a short-term toxicity test with fish, the LC50.96 h was higher than 370 µg/L and the NOEC was 370 µg/L.

Additional information

The acute toxicity of 2-ethylanthraquinone to guppies (Poecilia reticulata, Poeciliidae) was tested according to OECD TG 203 at nominal test concentrations of 250 and 500 µg /L in ISO-water (solubility limit 254 µg/L). The test substance was dissolved in DMSO prior to the preparation of test solutions due to its low water solubility. As 2-ethylanthraquinone is highly unstable in water under influence of light, the test was conducted under reduced light conditions (<100 lux) to reduce the decrease in test concentration. In addition, each 24 hours the test solutions were renewed. Samples of the test solutions were taken 0, 24, 48, 72 and 96 hours after test initiation, before and after renewal of the test solutions, and analysed with HPLC. Based on the mean measured test concentrations the LC50 after 96 h was higher than 370 µg/L and the NOEC - no observed effect concentration - was 370 µg/L.