5-nitroisophthalic acid

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

Experiment test result performed using standard test guideline

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

3-nitrobenzoic acid

EC Number:

204-508-5

EC Name:

3-nitrobenzoic acid

Cas Number:

121-92-6

Molecular formula:

C7H5NO4

IUPAC Name:

3-Nitrobenzoic acid

Test material form:

solid

Details on test material:

- Name (IUPAC): 3-Nitrobenzoic Acid
- Molecular formula: C7H5NO4
- Molecular weight: 167.1195 g/mol
- Smiles notation: c1(cc(ccc1)[N+](=O)[O-])C(=O)O
- InChl: 1S/C7H5NO4/c9-7(10)5-2-1-3-6(4-5)8(11)12/h1-4H,(H,9,10)
- Substance type: Organic
- Physical state: yellow crystalline powder

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Details on test solutions:

The stock solution 100 mg/l was prepared by dissolving test chemical in OECD growth medium. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name:
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Remarks on exposure duration:

±1 hour

Test conditions

Test temperature:

23±2°C

pH:

At concentration 10 mg/l: 7.7 (changed to 7.9 during test)
At concentration 18 mg/l: 7.6 (changed to 7.7 during test)
At concentration 32 mg/l: 7.4 (changed to 7.3 during test)
At concentration 58 mg/l: 7.1 (changed to 6.9 during test)
At concentration 100 mg/l: 6.4 (changed to 5.2 during test)
Control: 8.1 (changed to 8.3 during test)

Nominal and measured concentrations:

0, 10, 18, 32, 58, 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

106.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 95% CL: 98.6-114.9

Results with reference substance (positive control):

Results with reference substance valid
- EC50: 0. 77 mg/L

Reported statistics and error estimates:

ErC50 is calculated from the inhibition of growth rate by non-linear regression using software Prism 4.0, GraphPad.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 106.4 mg/L on the basis of effects on growth rate in a 72 hour study.

Executive summary:

An experiment was conducted to determine the toxicity of test chemical to aquatic algae by using OECD OECD Guideline 201 (Alga, Growth Inhibition Test). The test organisms used in this study was Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). The stock solution 100 mg/l was prepared by dissolving test chemical in OECD growth medium. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. The nominal concentrations of test chemical used were 0, 10, 18, 32, 58, 100 mg/l. The test system used was 50 mL glass vessel and Initial cells density used was 5x10E3 cells/ml and 3 replicates per concentration. The experiment was carried out in static system in freshwater and various concentrations of test chemical exposed to Desmodesmus subspicatus for 72 h and at temperature 23±2 °C. The reference substance used was Potassium dichromate. ErC50 is calculated from the inhibition of growth rate by non-linear regression using software Prism 4.0, GraphPad.

The EC50 value of reference substance was observed to be 0. 77 mg/L.

After 72 h exposure of test chemical to Desmodesmus subspicatus the effective concentration at which 50 % growth inhibition observed EC50 value was determined to be 106.4 mg/L (95% CL: 98.6-114.9 mg/l).

This EC50 value indicates that the substance test substance is likely to be non-hazardous to aquatic algae and cannot be classified as toxic and not classified as per the CLP criteria