Disodium 2-(11-oxido-3-oxo-3H-dibenzo[c,h]xanthen-7-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:

key study

Study period:

2018-02-15 to 2018-10-26

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)

Version / remarks:

13 April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0.6, 1.3, 2.9, 6.4, 14.0 and 30.9 mg/L
- Sampling method: Analysis of test concentration and stability of the test item was performed at the beginning of the test (0 hour) and day 0 and at the end of the test (48 hours) from all test concentrations. 15 mL of samples were collected in duplicates from each group.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Stock solution was freshly prepared prior to exposure, by weighing required quantity of test item in a beaker; small volume of reconstituted water was added and mixed well using a glass rod. After test item was completely soluble, the test formulation was transferred into a measuring cylinder and the beaker was rinsed with reconstituted water and transferred again to the measuring cylinder. Rinsing process was repeated until the complete transfer of test contents. Stock solution prepared was kept on magnetic stirrer to maintain homogeneity. Test medium of chosen concentration was prepared by dilution of stock solution.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: Environmental and Molecular Toxicology Division, Department of Zoology, Kamataka University, Karnataka, India.
- Age at study initiation: Less than 24 hours
- Feeding during test: No

ACCLIMATION
- Acclimation period: 48 h
- Acclimation conditions: same as test
- Type and amount of food: Daphnids were fed with live algal cells (Pseudokirchneriella subcapitata) of 2 mL per liter during the acclimatization.
- Feeding frequency: Daphnids was fed with live algal cells at the beginning and on Day 2 of acclimatization.
- Health during acclimation: No signs of stress

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

212 mg/L of CaCO3

Test temperature:

20.1 - 20.9 °C

pH:

7.46 - 7.91

Dissolved oxygen:

6.25 - 6.84 mg/L

Salinity:

not applicable.

Conductivity:

no data.

Nominal and measured concentrations:

Nominal: 0.6, 1.3, 2.9, 6.4, 14.0 and 30.9 mg/L
Measured: 0.58, 1.35, 2.91, 6.67, 14.55 and 32.66 mg/L (after 48 hours)

Details on test conditions:

TEST SYSTEM
- Test vessel: rectangular beaker
- Type: open
- Material, size: Glass, 100 mL
- Aeration: water was aerated prior to use for the test so that the dissolved oxygen concentration has reached saturation.
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Culture medium different from test medium: No

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 hours of light and 8 hours dark.

EFFECT PARAMETERS MEASURED:
- Each test vessel was observed for immobilized Daphnids at 24 and 48 hours after the beginning of the test, in addition any abnormal behavior or appearance was recorded.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 0.01, 0.1, 1.0, 10.0, 50.0 and 100.0 mg/L
- Results used to determine the conditions for the definitive study: During the range finding study, no immobility was observed in control and in the tested concentrations of 0.01 and 0.1 mg/L during the 48 hour exposure period. In the tested concentrations of 1.0, 10.0, 50.0 and 100.0 mg/L during the 48 hour exposure period an immobilization of 10, 50, 100 and 100 % was observed. Based on the results of the range-finding study, the main study was conducted at concentrations of 0.6, 1.3, 2.9, 6.4, 14.0 and 30.9 mg/L of test item using a geometric factor of 2.2)

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

6.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CI: 4.778 - 9.116

Duration:

48 h

Dose descriptor:

LOEC

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.6 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: Lethargy
- Mobility of control: 100 %
- Other adverse effects control: No
- Abnormal responses: Lethargy, localisation at the bottom of the beaker.
- 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: No

Results with reference substance (positive control):

- Results with reference substance valid? Yes
- Relevant effect levels: 0.12, 0.24, 0.48, 0.96, 1.92 mg/L
- Limit test: No
- Dose-response test: Yes
- EC50: 0.57 mg/L

Reported statistics and error estimates:

Data are analysed by statistical methods (Finney’s probit analysis) to calculate the EC50 with confidence limits.

Table 1: Test concentration analysis in test media during main study (reconstituted water)

Day 0 (0 Hour)			Day 2 (48 Hours)
Nominal concentration (mg/L)	Conc. Obtained (mg/L)	% Recovery	Nominal concentration (mg/L)	Conc. Obtained (mg/L)	% Recovery
0.0	-	-	0.0	-	-
0.60	0.57	94.17	0.60	0.58	95.84
1.30	1.29	98.85	1.30	1.35	103.85
2.90	2.84	97.76	2.90	2.91	100.18
6.40	6.43	100.47	6.40	6.67	104.22
14.00	14.28	102.00	14.00	14.55	103.93
30.90	31.64	102.40	30.90	32.66	105.68

 Results reported that determined test concentrations at the 0 hour and stability at 48 hour were in the acceptable range of 20 % recovery to the nominal concentrations.

Validity criteria fulfilled:

yes

Conclusions:

In a short-term toxicity study in Daphnia magma according to OECD guideline 202, an EC50 of 6.6 mg/L (95 % CI: 4.778 to 9.116 mg/L) was determined.

Executive summary:

The test item was evaluated for acute toxicity on Daphnia magma according to OECD guideline 202. Based on the results of a range finding study test item concentrations of 0.6, 1.3, 2.9, 6.4, 14.0 and 30.9 mg/L were tested along with untreated control and positive control (potassium dichromate). 5 Daphnids/dose were exposed to the test item by aqueous exposure (treatment) under static conditions. Signs of toxicity and immobility were recorded after 24 and 48 hours. No clinical signs of toxicity were observed in control and in the tested concentration of 0.6 mg/L during the 48 hour observation period. Immobilization and lethargy were observed in the tested concentrations of 1.3, 2.9, 6.4 and 14.0 mg/L during the 48 hour observation period. Percent immobility of 15, 25, 40 and 65 % were observed in the tested concentrations of 1.3, 2.9, 6.4 and 14.0 mg/L. 100 % immobilization was observed in the highest concentration of 30.9 mg/L after 48 hours.

Based on these results, an EC50(48 h) of 6.6 mg/L (95 % CI: 4.778 to 9.116 mg/L) was determined. The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) over the 48 hour exposure period were found to be 0.6 and 1.3 mg/L, respectively.

Description of key information

In a short-term toxicity study in Daphnia magma according to OECD guideline 202, an EC50 of 6.6 mg/L (95% CI: 4.778 to 9.116 mg/L) was determined.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

6.6 mg/L

Additional information

The test item was evaluated for acute toxicity on Daphnia magma according to OECD guideline 202. Based on the results of a range finding study test item concentrations of 0.6, 1.3, 2.9, 6.4, 14.0 and 30.9 mg/L were tested along with untreated control and positive control (potassium dichromate). 5 Daphnids/dose were exposed to the test item by aqueous exposure (treatment) under static conditions. Signs of toxicity and immobility were recorded after 24 and 48 hours. No clinical signs of toxicity were observed in control and in the tested concentration of 0.6 mg/L during the 48 hour observation period. Immobilization and lethargy were observed in the tested concentrations of 1.3, 2.9, 6.4 and 14.0 mg/L during the 48 hour observation period. For immobility a percent of 15, 25, 40 and 65 % were observed in the tested concentrations of 1.3, 2.9, 6.4 and 14.0 mg/L. 100 % immobilization was observed in the highest concentration of 30.9 mg/L after 48 hours.

Based on these results, an EC50(48 h) of 6.6 mg/L (95 % CI: 4.778 to 9.116 mg/L) was determined. The No Observed Effect Concentration (NOEC) and Lowest Observed Effect Concentration (LOEC) over the 48 hour exposure period were found to be 0.6 and 1.3 mg/L, respectively.