Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
The stock solution 200.0 mg/L was prepared in reconstituted water. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age: Young daphnids, aged less than 24 hours used at the start of the test and they should not be first brood progeny.
- Feeding during test : Without feeding

ACCLIMATION
- Acclimation period: No data
- Acclimation conditions (same as test or not): No data
- Type and amount of food: No data
- Feeding frequency: No data
- Health during acclimation (any mortality observed): No data

QUARANTINE (wild caught)
- Duration: No data
- Health/mortality: No data

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

48 h ± 1 h

Test temperature:

20 °C ± 1 °C

pH:

Sample at concentration 100.0 mg/L : pH = 7.9 changed to pH = 7.8 during the test,
Control: pH = 7.8 did not change during the test.

Dissolved oxygen:

Higher than 8.0 mg/L both in the control and the sample

Nominal and measured concentrations:

Nominal concentrations: 0, 2.5, 5,10, 20, 40, 80 and 100 mg/L, respectively

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- Material, size, headspace, fill volume: 25 ml
- Aeration: no data
- No. of organisms per vessel: 5 pieces
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): No data
- No. of vessels per vehicle control (replicates): No data
- Biomass loading rate: No data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Natural water (surface or ground water), reconstituted water or dechlorinated tap water are acceptable as culturing and dilution water if D. magna survives in it for the duration of the culturing, acclimation and testing without showing signs of stress. Waters in the range pH 6 to pH 9, with hardness between 140 mg/l and 275 mg/l (as CaCO3) are recommended.As an example, the preparation of dilution water meeting the requirements is described below.Dissolve known quantities of reagents in water. The dilution water prepared shall have a pH of 7.8 ± 0.5, a hardness of (225 ± 50) mg/l (expressed as CaCO3), a molar Ca + Mg ratio close to 4 + 1 and a dissolved oxygen concentration above 7 mg/l.

OTHER TEST CONDITIONS
- Adjustment of pH: Without adjustment
- Photoperiod: No - Darkness

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : EC50 was calculated using nonlinear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

8.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CI :5.7 – 11.3 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- 24h EC50 = 0.79 mg/l K2Cr2O7

Reported statistics and error estimates:

EC50 was calculated using non linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) of the test substance on Daphnia magna was determined to be 8.1 mg/L on the basis of mobiity inhibition effects in a 48 hour study.

Executive summary:

An acute immobilisation test was conducted for 48 hrs for assessing the short-term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used as a test organism. The stock solution 200.0 mg/L was prepared in reconstituted water. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted test water. 0, 2.5, 5,10, 20, 40, 80 and 100 mg/L, respectively nominal concentrations were used in the study. 5 daphnids per concentration were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. Observations including immobility, pH, Temperature, dissolved oxygen content were recorded in the interval of 24 and 48 hours. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 8.1 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 2 category as per the CLP criteria.

Description of key information

The study was conducted on two different species i.e. Daphnia magna and Artemia salina.After exposure period of 48 hours, effects were calculated. The median effective concentration (EC50 value) of the test substance on Daphnia magna was determined to be 8.1 mg/L on the basis of mobiity inhibition effects in a 48 hour study. Whereas on the basis of mortality of test organism Artemia Salina due to the test chemical exposure for 48 hours, the LC50 and LC100 value was observed to be > 87.9842 mg/ and 879.842 mg/l.

 

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

8.1 mg/L

Additional information

Summarized result from the various experimental sources for the determination of effect of test chemical on the aquatic invertebrates are as mentioned below:

An acute immobilisation test was conducted for 48 hrs for assessing the short-term toxicity of test chemical to aquatic invertebrate. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). Daphnia magna was used as a test organism. The stock solution 200.0 mg/L was prepared in reconstituted water. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample in reconstituted test water. 0, 2.5, 5, 10, 20, 40, 80 and 100 mg/L, respectively nominal concentrations were used in the study. 5 daphnids per concentration were used in the study. Effects on immobilisation were observed for 48 hours and conducted under the static system. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. Observations including immobility, pH, Temperature, dissolved oxygen content were recorded in the interval of 24 and 48 hours. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. Based on the immobilisation of Daphnia magna due to the exposure of test chemical for 48 hours, the EC50 value was determine to be 8.1 mg/l. EC50 value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified in aquatic chronic 2 category as per the CLP criteria.

 

Above study further supported by the next study from peer reviewed journal. Short term toxicity study to Artemia Salina was carried out for 24-48 hrs. The test chemical concentration used for the study was 879.842 mg/l and 87.9842 mg/l, respectively. A. salina eggs (encysted dried gastrulae) were commercially obtained and were stored at - 20°C. Eggs used in experiments were washed and stored at room temperature in a desiccator over anhydrous granular CaCl2. Larvae were obtained by incubating eggs in petri dishes containing muslin-filtered sea water at 30°C for 24 hours. The larvae were separated from shells, dead larvae and unhatched eggs by their phototactic movements toward a light source. Food dyes of various concentrations were placed in a petri dish, and sea water containing 20 to 30 larva e was added. After this was incubated at 30°Cfor 24 hours and 48 hours, larvae surviving were measured by direct count. The same method was tested from 5 to 6 times for each concentration, and the death rate was calculated. The study was performed under static conditions for 24 – 48 hrs at 30°C. Death was assumed to have occurred when there was no movement. The death rate was defined as the average of the percentage of deaths observed for 24 hours and 48 hours. Based on death rate or mortality of test organism, the 48 hr LC50 and LC100 value was determine to be 87.9842 mg/ and 879.842 mg/l.

 

On the basis of effects observation on the standard species Daphnia magna at the concentration of 8.1 mg/l, thus, test chemical consider to be toxic and classified in aquatic chronic category 2 as per the CLP classification criteria.