2-[[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-6-methoxy-3-methylbenzothiazolium acetate

Endpoint summary

Description of key information

Short term toxicity to fish:

Study was conducted to access the effect of test chemical on the growth of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test).The test substance was soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 1 hour stirring for achieving test concentrations of 6.25mg/L,12.5mg/L,25mg/L,50mg/L,100mg/L,respectively. This test solution was then added to the remaining three liters of water for achieving test concentrations of 100 mg/L and Zebra FishDanio reriowere exposed to these concentration for 96 hours.

Bowl 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. After 96 hours of exposure to test item to various nominal test concentrations, LC50 was determine to be >12.5 but <25 mg/l.100% mortality was observed in the concentration 25 mg/l . Based on the LC50, it can be consider that the chemical was toxic and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

Short term toxicity to aquatic invertebrate:

The short-term toxicity of the test substance to aquatic invertebrate is predicted using EPI Suite ECOSAR version 1.10. On the basis of effects observed in a static freshwater system during a 48 hr exposure, the effect concentration (EC50) for the substance is estimated to be 19.081 mg/L. Based on this value, it can be concluded that the test chemical can be considered as toxic to green algae at environmentally relevant concentrations and can be considered to be classified in aquatic chronic 3 as per the CLP classification criteria.

 

Toxicity to aquatic algae and cyanobacteria:

The short-term toxicity of the test substance to green algae is predicted using EPI Suite ECOSAR version 1.10. On the basis of effects observed in a static freshwater system during a 96 hr exposure, the effect concentration (EC50) for the substance is estimated to be34.935 mg/L. Based on this value, it can be concluded that the test chemical can be considered as toxic to green algae at environmentally relevant concentrations and can be considered to be classified in aquatic chronic category 3 as per the CLP classification criteria.

Toxicity of test material to microorganisms:

Data available for the test chemicals has been reviewed to determine the short term toxicity of fish of the test chemical .The studies are as mentioned below:

A screening method based on the measurement of the respiration rate of activated sludge for assessing the possible inhibitory effect of dyestuffs on aerobic waste-water bacteria. The test principle involves measuring the respiration rate of an activated sludge and comparing it with the respiration rate of the same activated sludge under identical conditions, but in the presence of the chemical under test. The test was carried out in activated sludge respiration rate apparatus with constant 20 ± 2°C and pH about 7-8. The test concentration used was 100 mg/l. OECD recommended synthetic sewage was used as feed, while activated sludge was obtained from a sewage works treating predominantly domestic sewage or from a sewage works treating predominantly industrial waste water. The respiration rate of an activated sludge and the respiration rate of activated sludge with test chemical were noted down. In order to calculate the inhibitory effect of a particular chemical at 100 mg/l test concentration its respiration rate is expressed as a percentage of the mean of the two control respiration rates. Thus, IC50 value (concentration for 50% inhibition of respiration rate) for the test chemical on activated sludge (aerobic bacteria) is determined to be10 - 100 mg/1 after 3 hrs of exposure.The test chemical is  likely to be toxic to microorganism  in the concentration  range of 10-100 mg/l

 

Additional information

Short term toxicity to fish:

Study was conducted to access the effect of test chemical on the growth of fish Danio rerio. Test conducted according to OECD Guideline 203 (Fish, Acute Toxicity Test).The test substance was soluble in water. Therefore, the stock solution was prepared by dissolving 1 g of the test substance in 1 liters of potable water (passed through reverse osmosis system) with continuous 1 hour stirring for achieving test concentrations of 6.25mg/L,12.5mg/L,25mg/L,50mg/L,100mg/L,respectively. This test solution was then added to the remaining three liters of water for achieving test concentrations of 100 mg/L and Zebra FishDanio reriowere exposed to these concentration for 96 hours.

Bowl 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. After 96 hours of exposure to test item to various nominal test concentrations, LC50 was determine to be >12.5 but <25 mg/l.100% mortality was observed in the concentration 25 mg/l . Based on the LC50, it can be consider that the chemical was toxic and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

Short term toxicity to aquatic invertebrate:

The short term toxicity of aquatic invertebrate was concluded based on the prediction of test material on aquatic invertebrate along with data of test reports

In the prediction ,the short-term toxicity of the test substance to aquatic invertebrate is predicted using EPI Suite ECOSAR version 1.10. On the basis of effects observed in a static freshwater system during a 48 hr exposure, the effect concentration (EC50) for the substance is estimated to be 19.081 mg/L. Based on this value, it can be concluded that the test chemical can be considered as toxic to green algae at environmentally relevant concentrations and can be considered to be classified in aquatic chronic 3 as per the CLP classification criteria.

The above prediction was supported by studies,Aim of this study was to assess the short term toxicity of test material to aquatic invertebrates 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 100 mg/l was prepared by dissolving orange powder in reconstituted water. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water. 0, 6, 10, 18, 32, 58 and 100 mg/lconcentrations 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 54.8 mg/L on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, substance is likely to be hazardous to aquatic invertebrate and can be classified as aquatic chronic 3 category as per the CLP classification criteria.

In another study , aim of this study was to assess the short term toxicity of test chemical to aquatic invertebrates daphnia magna. Study was performed according to the OECD guideline in a static system for the total exposure period of 48 hrs.

 The stock solution 100 g/l was prepared by dissolving white powder in acetone. Test solutions of required concentrationas were prepared by mixing the stock solution of the test sample with reconstituted test water. Acetone used as a solvent because of limited solubility of tested sample in water. 0, 0, 0.5, 1, 2, 4, 8, 16 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 be10.9 mg/L with the confidence interval of 9.9 - 11.9 mg/l on the basis of mobility inhibition effects in a 48 hour study. Based on the EC50 value, it can be concluded that the substance is likely to be hazardous to aquatic invertebrates and can be classified as aquatic chronic 3 category as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

The test material was evaluated for its potential to cause toxicity to aquatic algae based on the values obtained from predicted data and studied.
In prediction ,the short-term toxicity of the test substance to green algae is predicted using EPI Suite ECOSAR version 1.10. On the basis of effects observed in a static freshwater system during a 96 hr exposure, the effect concentration (EC50) for the substance is estimated to be34.935 mg/L. Based on this value, it can be concluded that the test chemical can be considered as toxic to green algae at environmentally relevant concentrations and can be considered to be classified in aquatic chronic category 3 as per the CLP classification criteria.

In a study ,the algal growth inhibition test was performed using as test material on Chlorella sp .Chlorella sp were grown on 500mL Erlenmeyer flask.Algae were added into 100mL of test water containing 50, 100, 150, 200 and 250 mg/L of 73.6, 67.9, 33.3, 25.0 and 16.6% concentration of test chemical . The flask was placed in an ambient temperature provided air and sealed with parafilm.Flasks were continuous illuminated (cool white fluorescent light approximately 120 mE/s/m2 or 6,000 lux at water level.  Determination of algal growth by measuring live cell count, Chlorophyll a, dry weight and absorbance at 720nm. The effect concentration of test chemical on Chlorella sp. was observed to be 10.8 mg/l. Based on the above effect concentration it can be considered that test material is toxic to aquatic algae and can be classified as aquatic chronic 3.

The above study was supported by another study ,freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the substance test material according to OECD Guideline 201. The test substance was dissolved in acetone and tested at the concentrations 0, 0, 0.5, 1, 2 and 4 mg/L.The stock solution 2 g/L was prepared by dissolving yellow powder in acetone. Test solutions of required concentrations were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. It was not possible to test higher substance concentrations due to solubility of the test substance.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 17.8 mg/L. Based on the ErC50, it can be concluded that the chemical was toxic and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

In a study , freshwater algal growth inhibition test was carried out on Desmodesmus subspicatus with the test substance according to OECD Guideline 201. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in DMSO/ OECD growth medium. The stock solution was kept in ultrasonic bath for 20min Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and tested at the concentrations 0, 2.5, 5, 10, 20 and 40 mg/L. Effects on the growth rate of the organism were studied. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be13.4 mg/L.

These value indicates that the substance is likely to be hazardous to aquatic algae and can be classified as Aquatic Chronic 3 as per the CLP criteria.

Toxicity of test material to microorganisms:

Data available for the test chemicals has been reviewed to determine the short term toxicity of fish of the test chemical .The studies are as mentioned below:

A screening method based on the measurement of the respiration rate of activated sludge for assessing the possible inhibitory effect of dyestuffs on aerobic waste-water bacteria. The test principle involves measuring the respiration rate of an activated sludge and comparing it with the respiration rate of the same activated sludge under identical conditions, but in the presence of the chemical under test. The test was carried out in activated sludge respiration rate apparatus with constant 20 ± 2°C and pH about 7-8. The test concentration used was 100 mg/l. OECD recommended synthetic sewage was used as feed, while activated sludge was obtained from a sewage works treating predominantly domestic sewage or from a sewage works treating predominantly industrial waste water. The respiration rate of an activated sludge and the respiration rate of activated sludge with test chemical were noted down. In order to calculate the inhibitory effect of a particular chemical at 100 mg/l test concentration its respiration rate is expressed as a percentage of the mean of the two control respiration rates. Thus, IC50 value (concentration for 50% inhibition of respiration rate) for the test chemical on activated sludge (aerobic bacteria) is determined to be10 - 100 mg/1 after 3 hrs of exposure.The test chemical is  likely to be toxic to microorganism  in the concentration  range of 10-100 mg/l