3-nitrobenzoic acid

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:

25.09.2017 - 27.09.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experiment test result performed using standard test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Principles of method if other than guideline:

Short term toxicity of test material to aquatic invertebrates was performed according to the 202 OECD guideline in a static system.

GLP compliance:

no

Analytical monitoring:

no

Details on test solutions:

The stock solution 200 mg/l was prepared by dissolving white powder in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain: Straus
- Source: Own breeding at University of Chemistry and Technology, Prague
- Age at study initiation (mean and range, SD): The animals used for the test shall be less than 24 h old and should not be first brood progeny
- Feeding during test: No feeding

ACCLIMATION - No data available

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

± 1 hr

Test temperature:

20±1°C

pH:

Control: 7.8 (Change to 7.6 during test)

Dissolved oxygen:

higher than 8.4 mg/L at the end of test

Nominal and measured concentrations:

0, 6.2, 12.4, 25, 50, 100, 200 mg/l.

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml glass vessel
- fill volume: 25 ml
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4

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.

Prepare the solutions specified below:
- Calcium chloride solution: Dissolve 117.6 g of calcium chloride dihydrate (CaCl2.2H2O) in water (4.2) and make up to 1 l with water (4.2).
- Magnesium sulfate solution: Dissolve 49.3 g of magnesium sulfate heptahydrate (MgSO4.7H2O) in water (4.2) and make up to 1 l with water (4.2).
- Sodium bicarbonate solution: Dissolve 25.9 g of sodium bicarbonate (NaHCO3) in water (4.2) and make up to 1 l with water (4.2).
- Potassium chloride solution: Dissolve 2.3 g of potassium chloride (KCI) in water (4.2) and make up to 1 l with water (4.2).

Mixing
Mix 2.5 ml of each of the four solutions and make up to 1 l with water.
The dilution water shall be aerated until the dissolved oxygen concentration has reached saturation and the pH has stabilized. If necessary, adjust the pH to 7.8 ± 0.5 by adding sodium hydroxide (NaOH) solution or hydrochloric acid (HCI). The dilution water prepared in this way shall not be further aerated before use.

- Sodium hydroxide solution, e.g. [NaOH] : 1 mol/l.
- Hydrochloric acid, e.g. [HCl] : 1 mol/l.

Reference substance:
Dissolve 600 mg of potassium dichromate (K2Cr2O7) in water and make up to 1 l with water (4.2).

OTHER TEST CONDITIONS
- Adjustment of pH: no adjustment done
- Photoperiod: No - Darkness
- Light intensity:

CALCULATION:
EC50 was calculated using non linear 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.:

71.3 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95% CL: 42.2-120.7 mg/l

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

96.7 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Without concentration 200 mg/l

Remarks:

95% CI was 68.6 - 136.4 mg/l

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.76 mg/L (24 hours)

Reported statistics and error estimates:

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

pH value:

Sample concentration (mg/l)	6.2	12.4	25.0		50.0	100.0	200.0
Start of the test	7.6	7.6		7.2	6.8	6.2	4.1
The end of the test	7.7	7.6		7.4	7.0	6.9	4.0

Validity criteria fulfilled:

not specified

Conclusions:

The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 71.3 mg/L on the basis of mobiity inhibition effects in a 48 hour study.

Executive summary:

Determination of the inhibition of the mobility of daphnids was carried out with the substance . Test was performed according to OECD Guideline 202.

The test substance was tested at the concentrations 0, 6.2, 12.4, 25, 50, 100, 200 mg/l. The stock solution 200 mg/l was prepared by dissolving white powder in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance, 3-Nitrobenzoic Acid in Daphnia magna was determined to be 71.3 mg/L for immobilisation effects. Tested substance is an acid and that is why the higher concentration the lower Ph. The optimum pH for daphnids is 6.0-6.9. The inhibition of the mobility of daphnids could be influenced by pH at the concentration 200 mg/l and that is why EC50 was calculated also for results without the concentration 200 mg/l with low pH. Adjustment of pH would change substance properties. The EC50 without 200 mg/l concentration of test chemical was 96.7 with 95% CI was 68.6-136.4 mg/l.

This value indicates that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP criteria.

Description of key information

Short term toxicity to aquatic invertebrate:

Determination of the inhibition of the mobility of daphnids was carried out with the substance . Test was performed according to OECD Guideline 202.

The test substance was tested at the concentrations 0, 6.2, 12.4, 25, 50, 100, 200 mg/l. The stock solution 200 mg/l was prepared by dissolving white powder in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance, 3-Nitrobenzoic Acid in Daphnia magna was determined to be 71.3 mg/L for immobilisation effects. Tested substance is an acid and that is why the higher concentration the lower Ph. The optimum pH for daphnids is 6.0-6.9. The inhibition of the mobility of daphnids could be influenced by pH at the concentration 200 mg/l and that is why EC50 was calculated also for results without the concentration 200 mg/l with low pH. Adjustment of pH would change substance properties. The EC50 without 200 mg/l concentration of test chemical was 96.7 with 95% CI was 68.6-136.4 mg/l.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

68.6 mg/L

Additional information

Short term toxicity to aquatic invertebrate:

Determination of the inhibition of the mobility of daphnids was carried out with the substance . Test was performed according to OECD Guideline 202.

The test substance was tested at the concentrations 0, 6.2, 12.4, 25, 50, 100, 200 mg/l. The stock solution 200 mg/l was prepared by dissolving white powder in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water. Effects on immobilisation were observed for 48 hours. The median effective concentration (EC50) for the test substance, 3-Nitrobenzoic Acid in Daphnia magna was determined to be 71.3 mg/L for immobilisation effects. Tested substance is an acid and that is why the higher concentration the lower Ph. The optimum pH for daphnids is 6.0-6.9. The inhibition of the mobility of daphnids could be influenced by pH at the concentration 200 mg/l and that is why EC50 was calculated also for results without the concentration 200 mg/l with low pH. Adjustment of pH would change substance properties. The EC50 without 200 mg/l concentration of test chemical was 96.7 with 95% CI was 68.6-136.4 mg/l.