Disodium 2-amino-5-[(4-sulphonatophenyl)azo]benzenesulphonate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

03.10.2017 - 06.10.2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Experimental test result performed using standard test guideline

Justification for type of information:

Data is from ABITEC lab report.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Principles of method if other than guideline:

Aim of this study was to evaluate the nature of chemical when comes in contact with the test organism. Test was conducted according to the OECD guideline 201.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): C.I. Acid Yellow 9
- Molecular formula: C12H11N3O6S2.2Na
- Molecular weight : 401.3301g/mol
- Substance type:Organic
- Physical state:Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Details on test solutions:

The test solution 100 mg/l was prepared by dissolving yellow powder in OECD growth medium.

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
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

23±2°C

pH:

Test at highest concentration: 8 (Change to 7.8 during tests)
Control: 8.0 (changed to 7.8 during test)

Nominal and measured concentrations:

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: 15ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 6

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)

Key result

Duration:

72 h

Dose descriptor:

other: IC1.6

Remarks:

%

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Only 1.6 % inhibition was observed after 72 hrs.

Results with reference substance (positive control):

- Results with reference substance valid
- EC50: 0.77 mg/L (24 hours)

Validity criteria fulfilled:

yes

Conclusions:

Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (C.I. Acid Yellow 9), the inhibitory concentration was 100 mg/l on that only 1.6 % inhibition was observed after the 72hrs incubation period.

Executive summary:

Aim of this study was to evaluate the nature of chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (C.I. Acid Yellow 9) when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The test solution 100 mg/l was prepared by dissolving yellow powder in OECD growth medium. Effects on the growth rate of the organism were studied.

Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical disodium 2-amino-5-[(4-sulfonatophenyl) diazenyl]benzenesulfonate (C.I. Acid Yellow 9), the inhibitory concentration was 100 mg/l on that only 1.6 % inhibition was observed after the 72hrs incubation period. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

Description of key information

Aim of this study was to evaluate the nature of chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (C.I. Acid Yellow 9) when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The test solution 100 mg/l was prepared by dissolving yellow powder in OECD growth medium. Effects on the growth rate of the organism were studied. Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical disodium 2-amino-5-[(4-sulfonatophenyl) diazenyl]benzenesulfonate (C.I. Acid Yellow 9), the inhibitory concentration was 100 mg/l on that only 1.6 % inhibition was observed after the 72hrs incubation period. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

100 mg/L

Additional information

Summarized result for the toxicity of chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate on the growth of aquatic algae which are as follows:

In the first key study for the target chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (2706 -28 -7) from ABITEC report 2017, toxicity was measured.

Aim of this study was to evaluate the nature of chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (C.I. Acid Yellow 9) when comes in contact with the test organism Desmodesmus subspicatus (previous name: Scenedesmus subspicatus). Test was conducted according to the OECD guideline 201. The test solution 100 mg/l was prepared by dissolving yellow powder in OECD growth medium. Effects on the growth rate of the organism were studied. Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical disodium 2-amino-5-[(4-sulfonatophenyl) diazenyl]benzenesulfonate (C.I. Acid Yellow 9), the inhibitory concentration was 100 mg/l on that only 1.6 % inhibition was observed after the 72hrs incubation period. This value indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

Similarly first study was supported by the second supporting study from the UERL report for the target chemical disodium 2-amino-5-[(4-sulfonatophenyl)diazenyl]benzenesulfonate (2706 -28 -7).

The effect of test item disodium 2-amino-5-[(4-sulphonatophenyl)azo]benzenesulphonate, (CAS No. 2706-28-7) was studied on the growth of fresh water green alga Chlorella vulgaris. The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 6.25mg/L, 12.5mg/L, 25mg/L, 50mg/L, 100mg/L and 200mg/L. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC25 calculated graphically through probit analysis was observed to be 239.918mg/L and the EC50 value was determined to be > 200 mg/l, respectively. Thus, based on the EC50 value, test substance can be considered as non-toxic to aquatic organisms and thus cannot be classified as hazardous as per the CLP criteria.

Based on the above studies chemical was consider as nontoxic and not classified as per the CLP classification criteria.