4'-aminoazobenzene-4-sulphonic acid

Endpoint summary

Description of key information

Short term toxicity to fish:

Study was conducted to assess the effect of test chemical on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test). The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 62.5 mg, 125 mg, 250 mg ,500mg & 100 mg of the test substance in 10 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 6.5 mg/L, 12.5 mg/L, 25 mg/L, 50 mg/L & 100 mg/L, respectively. Potable water (passed through reverse osmosis system) was used and Zebra Fish Danio rerio were exposed to these concentration for 96 hours. Plastic aquaria containing 2 liters of potable water (passed through reverse osmosis system) were loaded with 8 fishes. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Aeration in test vessels was provided 1 day before the start of experiment. After 96 hours of exposure of test item to various nominal test concentrations, LC0 was determine to be 50 mg/l on the basis of mortality effect observation and LC100 at 100 mg/l.

Long term toxicity to fish:

Based on the prediction done using ECOSAR class, the long term toxicity on fish was predicted for test substance. On the basis of no effects observed in a semi-static freshwater system, the NOEC value for the substance is estimated to be 53.554 mg/l for fish for 28 days of exposure duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to fish at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria. 

 

Short term toxicity to aquatic invertebrates:

2nd: The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 500 mg/L on the basis of mobility inhibition effects in a 48 hour study.

3rd: The effect concentration (EC50) for the test substance, in Daphnia magna was determined to be > 100 mg/L on the basis of mobility inhibition effects in a 48 hour study. Only 4% inhibition was determine after 48 hrs of exposure.

Thus based on the all above studies and effects, test chemical consider to be nontoxic to the aquatic invertebrates and hence not classified as per the CLP classification criteria.

Long term toxicity to aquatic invertebrates:

Based on the prediction done using ECOSAR class, the long term toxicity on aquatic invertebrate daphnia was predicted for test substance. On the basis of no effects observed in a flow-through freshwater system, the NOEC value for the substance is estimated to be 1.274 mg/l for aquatic invertebrate for 21 days of exposure duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to daphnia at environmentally relevant concentrations and can be considered as not-classified as per the CLP classification criteria. 

Toxicity to algae and cyanobacteria:

2nd: The median effective concentration (ErC50) for the test substance, on a freshwater algae Desmodesmus subspicatus was determined to be 129.4 mg/L on the basis of effects on growth rate in a 72 hour study.

3rd: Based on the growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical, the inhibitory concentration was 100 mg/l on that only 1.6 % inhibition was observed after the 72hrs incubation period.

4th: After 72 hours of exposure of test chemical to various nominal test concentration, EC50 calculated from equation through probit analysis was determine to be > 200 mg/l.

Based on the overall data from various sources, it can be concluded that the substance is considered to be not toxic to aquatic environment (algae and cyanobacteria) and cannot be classified as toxic as per the criteria mentioned in CLP regulation.

Toxicity to microorganisms:

2. Based on the growth rate inhibition of bacteria after exposure of 24 hrs with the test chemical, no effect were observed on the growth of bacteria. The EC0 was determine at the 500 mg/l.  

3. Based on the growth rate inhibition of bacteria after exposure with test chemical, the EC0 was determine at > 2500 mg/l.

Thus based on the overall studies for the test chemical, chemical consider to be nontoxic and the toxicity ranges from the concentration of 500 - 2500 mg/l.

Additional information

Aquatic toxicity:

Summarized result for the toxicity of test chemical on the growth and mortality of aquatic life’s including fish, invertebrates, algae and microorganism were studied and are as mention below:

Short term toxicity to fish:

Based on the short term toxicity study available for the test chemical, studies were reviewed to determine the toxic nature of test chemical on the mortality of fish. The studies are as mentioned below:

 

Study was conducted to access the effect of test chemical on the mortality of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test). The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 62.5 mg, 125 mg, 250 mg ,500mg & 100 mg of the test substance in 10 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 6.5 mg/L, 12.5 mg/L, 25 mg/L, 50 mg/L & 100 mg/L, respectively. Potable water (passed through reverse osmosis system) was used and Zebra Fish Danio rerio were exposed to these concentration for 96 hours. Plastic aquaria containing 2 liters of potable water (passed through reverse osmosis system) were loaded with 8 fishes. A static procedure was used for the study and it was conducted in compliance with the OECD guideline 203. Aeration in test vessels was provided 1 day before the start of experiment. After 96 hours of exposure of test item to various nominal test concentrations, LC0 was determine to be 50 mg/l on the basis of mortality effect observation and LC100 at 100 mg/l.

 

 

Long term toxicity to fish:

Various long term studies available for the test chemical and structually and functionally similar read across chemicals were reviewed to determine the toxic nature of test chemical on the mortality of fish. The studies are as mentioned below:

 

Based on the prediction done using ECOSAR class, the long term toxicity on fish was predicted for test substance. On the basis of no effects observed in a semi- static freshwater system, the NOEC value for the substance is estimated to be 53.554 mg/l for fish for 28 days of exposure duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to fish at environmentally relevant concentrations and can be considered not-classified as per the CLP classification criteria. 

 

Above data was supported by the second study from authoritative database. Aim of this study was to evaluate the long term effect of test chemical on the on fish. Test conducted in accordance with OECD Guideline 204 (Fish, Prolonged Toxicity Test: 14-day Study). Before use chemical analytically monitored by HPLC. Test performed under the flow through system. 100, 50, 25.0, 12.5, 6.25 mg/L (geometric ratio 2.0), control nominal concentrations were used. Test liquid volume 3.6 L per concentration were added with 10 test organism per vessel. After the exposure of complete 21 days effect were measured. The lethal concentration (LC50) value of test chemical on freshwater fish in a 14 & 21 days study was determine to be 100 & > 100 mg/L and NOEC value was observed to be 25 mg/l. Based on this value, chemical consider to be nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Based on the above data, it can be concluded that the chemical was nontoxic to the fish and thus not classified as per the CLP classification criteria.

 

Short term toxicity to aquatic invertebrates:

Various short term studies available for the test chemical and structurally and functionally similar read across chemical were reviewed to determine the toxic nature of test chemical on the mobility of aquatic invertebrates. The studies are as mentioned below:

Aim of this study was to access the short term toxicity of test chemical to aquatic invertebrate daphnia magna. Study was performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs. The stock solution 200 mg/L was prepared by dissolving light grey powder in reconstituted water. The test solutions of required concentration as were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 5, 10, 25, 50, 100, 200 mg/l nominal concentrations were used in the study. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance, in Daphnia magna was determined to be 500 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, it indicates that the substance is likely to be non-hazardous to aquatic invertebrates and cannot be classified as per the CLP criteria.

 

 

First study was supported by the second study from experimental report. Aim of the study was to determine the short term toxicity of test chemical to aquatic invertebrates by performing test according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) in a static system. The stock solution 100 mg/l was prepared by dissolving yellow powder in reconstituted water. Effects on immobilisation were observed for 48 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. 25 daphnia magna were used in the study, out of that only 1 daphnia magna shows immobility and the remaining were mobile. The effect concentration (EC50) for the test substance, in Daphnia magna was determined to be > 100 mg/L on the basis of mobility inhibition effects in a 48 hour study. Only 4% inhibition was determine after 48 hrs of exposure. Based on the inhibitory concentration chemical was consider as nontoxic and not classified as per the CLP classification criteria.

 

Thus based on the all above studies and effects, test chemical consider to be nontoxic to the aquatic invertebrates and hence not classified as per the CLP classification criteria. 

 

Long term toxicity to aquatic invertebrates:

 

Based on the various long term studies available for the test chemical and structurally and functionally similar read across chemical, studies were reviewed to determine the toxic nature of test chemical on the mobility and reproduction of aquatic invertebrates. The studies are as mentioned below:

 

Based on the prediction done using ECOSAR class, the long term toxicity on aquatic invertebrate daphnia was predicted for test substance. On the basis of no effects observed in a flow-through freshwater system, the NOEC value for the substance is estimated to be 1.274 mg/l for aquatic invertebrate for 21 days of exposure duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to daphnia at environmentally relevant concentrations and can be considered as not-classified as per the CLP classification criteria. 

 

Similar acute Immobilization Test of test chemical was studied on Daphnia magna by providing the exposure period of 21 days. Test was performed according to the OECD Guideline 211 (Daphnia magna Reproduction Test). Test performed in the semi-static system. Control, 100, 32, 10 mg/L nominal concentration was added in the test vessel filled with 80 ml of test solution. Test conducted in the ten replicates, 10 daphnia magna per concentration (1 per vessel was added). Based on the effect of chemical on the normal activity of daphnia magna after 21 days, the EC50 was determine to ≥ 100 mg/l and NOEC was observed at 100 mg/l. Thus based on the EC50, it can be concluded that the test chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria. 

 

In the third study which was conducted to determine the long term toxicity of test chemical on the mortality rate of daphnia magna. Test conducted in the open system under the semi-static method. 4 replicates were used in which 10 organisms were used in each replicates. Control of DMSO: HCO-40 was 9:1 (100 mg/kg). Test conducted on the nominal concentration for 7 days, 14 days and 21days. After the exposure of chemical lethal concentration was measured. Based on the mortality rate of daphnia magna due to the long period exposure with chemical, the LC50 value was observed at 13 mg/l, 10 mg/l and 9.7 mg/l for 7 days, 14 days and 21 days of exposure. The EC50 was 4.4 and 9.1 after 14 and 21 days of exposure. Based on the LC50, it can be concluded that the chemical was nontoxic and not classified as per the CLP classification criteria.

 

Thus based on the above effects and studies available on the long term effect on aquatic invertebrate, test chemical consider to be nontoxic to the aquatic invertebrates and hence not classified as per the CLP classification criteria.

 

Toxicity to algae and cyanobacteria:

Various short term studies and other data available for the test chemical including structurally and functionally similar read across chemical were reviewed to determine the toxic nature of test chemical on the growth of aquatic algae and cyanobacteria. The studies are as mentioned below:

 

Freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the test substance according to OECD Guideline 201. The test substance was dissolved in OECD growth medium and tested at the concentrations 0, 2.2, 11, 25, 55 and 120 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (ErC50) for the test substance, in Desmodesmus subspicatus was determined to be 129.4 mg/L. Potassium dichromate (K2Cr2O7) were used as a reference positive control. Effects on immobilisation were observed for 48 hours by using nonlinear regression by the software Prism 4.0. Based on this ErC50 value and after comparing with CLP criteria for aquatic classification of the substance it is concluded that the substance does not exhibit toxicity to aquatic algae (Desmodesmus subspicatus) and not classified as toxic as per the CLP classification criteria. 

 

Similarly in the second first freshwater study was to evaluate the nature of test chemical 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, the inhibitory concentration was > 100 mg/l. At 100 mg/l 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.

 

Above studies was supported by the experimental study report from experimental data. The effect of test item 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, 200mg/L. The test solution was prepared in aseptic condition. The test item was prepared by adding 50 mg of test item in 250 ml of BBM to get the final concentration of 200 mg/L. This stock solution was kept for stirring/ sonication for 30 minutes to obtain a homogenous solution for the experiment. The test concentrations were chosen according to the available data of the test item. The concentrations chosen were set up to the water solubility limit. The remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment. Test was performed in static manner at proper requirement of pH and temperature. The microscopic observations were noted down in each of the control vessel. All the cells appeared healthy, round and green throughout the study duration in the control. Also, the drift in pH in the control vessels did not increase by >1.5 units when observed on 72 hours as compared to 0 hours. The average pH drift observed in the control vessels was 0 units. After 72 hours of exposure of test chemical to various nominal test concentration, EC50 calculated from equation through probit analysis was determine to be > 200 mg/l. Based on the EC50, it can be concluded that the chemical was nontoxic and can be consider to be not classified as toxic as per the CLP classification criteria.

 

Based on the overall data from various sources, it can be concluded that the substance is considered to be not toxic to aquatic environment (algae and cyanobacteria) and cannot be classified as toxic as per the criteria mentioned in CLP regulation.

Toxicity to microorganisms:

Various studies available for the test chemical and structurally and functionally similar read across chemical were reviewed to determine the toxic nature of test chemical on the growth and other activity of microorganisms. The studies are as mentioned below:

 

Aim of this study was to determine the effect of test chemical on the growth of bacteria. Unadapted biological waste water treatment plants were used. Test conducted for 24 hrs. Based on the growth rate inhibition of bacteria after exposure of 24 hrs with the test chemical, no effect were observed on the growth of bacteria. The EC0 was determine at the 500 mg/l. based on the EC0 chemical can be consider to be nontoxic to the growth of microorganisms.  

 

Above study was supported by the second study from peer reviewed journal. Study was conducted to determine the level of effect of test chemical on the growth of bacteria. Based on the growth rate inhibition of bacteria after exposure with test chemical, the EC0 was determine at > 2500 mg/l. As no effect were observed on the growth of bacteria chemical consider to be nontoxic.

 

Thus based on the overall studies for the test chemical, chemical consider to be nontoxic and the toxicity ranges from the concentration of 500 - 2500 mg/l.

 

Based on the short and long term toxicity studies on fish, aquatic invertebrates and algae, chemical consider to be nontoxic and thus not classified as per the CLP classification criteria.