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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

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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 test solution was prepared by dissolving 100 mg, 200 mg, 400 mg, 800 mg & 400 mg of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L & 400 mg/L, respectively and Zebra Fish Danio rerio were 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 > 400 mg/l . Based on the LC50, it can be consider that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Long term toxicity to fish:

Using the EPI Suite ECOSAR, the long term toxicity on fish was predicted for test substance. On the basis of no effects observed in a freshwater system, the no observed effect concentration (NOEC) value for the substance is estimated to be 307.146 mg/l for fish for 28 d duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to fish and can be considered to be not classified as per the CLP classification criteria.

 

Short term toxicity to aquatic invertebrates:

The objective of this study was conducted to evaluate the Acute toxicity of test chemical  to the Daphnia sp., (Daphnia magna). The study was performed in compliance with following regulatory guideline: OECD Guideline for Testing of chemicals OECD NO. 202, Adopted by the Council on 13 April 2004, Daphnia sp. Acute Immobilization Test.

Solubility of test item was performed by dissolving in the natural water (ground water) at 254 mg/L. Based on the solubility test, a vehicle was selected as a natural water for the test in the study.

Stability of the test item in natural water determined by analyzing the test concentrations of 1 and 100.0 mg/L at 0 hour, 24 hour and 48 hour showed that the test item concentration remained 80% to 120%(96.81 to 98.34 %) with respect to initial measured concentration and hence the dose verification for limit test was performed at the beginning and at the termination of the test.

The brood daphnids were acclimatized 48 hours prior to the test item exposure in dilution water. Less than 24 hours old daphnids were collected from the acclimatized gravid females and exposed to the test item. After exposure on day 0, daphnids were observed for Immobilization at 24 and 48 hours.

Range finding test was conducted with test concentration of 6.25, 12.5, 25, 50 and 100 mg/L along with a control group without test item by static method. Each concentration contained two replicates and 5(five) Daphnids per replicate. Test item was formulated in natural water. The treated Daphnids were maintained in a condition. No immobilization (percent) and any abnormal behaviour observed in control group and in all the tested concentrations of 6.25, 12.5, 25, 50 and 100 mg/L for a period of 48 hours.

Based on the results of range finding test, the limit test was conducted with a test concentration of 100 mg/L along with a control group without test item by static method. A limit test concentration contained four replicates and 5(five) Daphnids per replicate. Test item was formulated in natural water. The treated Daphnids were maintained in a test condition. No immobilization (percent) and any abnormal behaviour observed in control group and a limit tested concentration of 100 mg/L for a period of 48 hours.

During thelimit test period, all the beakers were incubated in the roomunder test condtion.The pH of the control at the start and at termination of the study was 6.8 and therefore did not vary more than 1.5 units during the study. The pH of the limit test concentrations was 6.9 at the beginning of the test and 7.0 at test termination. The room temperature was between 19.0°C and 20.9°C. The temperature of the control and a limit test concentrationat the beginning of the test and at test termination was 20°C and 21°C. The Dissolved oxygen of the control at the start and at termination of the study was 8.2 and 5.2 mg/L. The Dissolved oxygen of the limit test concentration was 8.1 at the beginning of the test and 4.9 mg/L at test termination. The mean intensity of light ranged from 1425 to 1443 Lux.

The test item available in the test medium (natural water) was determined by a validated HPLC system. The test item concentration of test chemical in the test medium at the initiation (0 hour) 97.12% and after 48 hours 96.40 % of the nominal test concentrations. As the measured concentration was within 80 to 120% of the nominal concentration during the exposure period.

Based on the results of this study, the EC50value for 48 hours of Sodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-ide was found to be greater than 100 mg/L.The results observed in the present study meets all the validity criteria as per OECD 202 Test guideline. Based on the outcomes test chemcial cannot be classified

Long term toxicity to aquatic invertebrates:

Based on the prediction done using the EPI Suite ECOSAR, the long term toxicity on daphnia magna was predicted for test substance. On the basis of effects observed in a freshwater system, the no observed effect concentration (NOEC) value for the substance is estimated to be 119.839 mg/l for daphnia magna for 21 day duration. On the basis of this value, it can be concluded that the test chemical can be considered as non-toxic to daphnia magna and can be considered to be not classified as per the CLP classification criteria.

Toxicity to algae and cyanobacteria:

The study was conducted to assess the effects ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-ideon the growth of green Algae,Pseudokirchneriella subcapitataaccording to the OECD Test Guideline 201, ‘Freshwater Algae and Cyanobacteria, Growth Inhibition Test’ (March, 2006) and Council Regulation (EC) No. 440/2008, Annex Part C.3: ‘Algal Inhibition Test’.

The test concentrations were prepared in OECD TG 201 media by dilution of stock and transferred 100 ml of each test solution into 250 ml Erlenmeyer flasks. The control and treatment flasks were inoculated withPseudokirchneriella subcapitatapre-cultured for 3 days and tested at an initial cell density of 1 × 104cells per ml, incubated under test condition for 72 hours. The cells were counted using an Improved Neubaur’s Haemocytometer under illumination of the microscope at 24, 48 and 72 hour after inoculation.

Weighed 25.5 mg of the test item in a 100 ml volumetric flask dissolved and made up to the mark usingOECD mediumand the resulting concentration was 255 mg/L coded as stock.Based on the solubility test, a vehicle was selected as a OECD medium for the test in the study.

Stability of the test item in OECD medium determined by analyzing the test concentrations of 1 and 100.0 mg/L at 0 hour, 24 hour, 48 hour and 72 hour showed that the test item concentration remained 80% to 120% (95.06 to 97.4%) with respect to initial measured concentration and hence the dose verification for limit test was performed at the beginning and at the termination of the test.

A range finding test was conducted with test item concentrations of 6.25, 12.5, 25, 50 and 100 mg/L with three replicates per test item concentration and six replicates for the control to assess the growth inhibition of alga in terms of growth rate and yield. The control group was used with OECD medium without test item.No significant changes in the appearance of algae cells were observed in control and in the test concentrations during 72 hours test period. At the end of 72 hour observation,0.48%, 0.61%, 1.13%, 2.03 % and 2.65% in terms of inhibition of growth rate and 2.32%, 2.89%, 5.25%, 9.16% and 11.77% in terms ofinhibition of yield was observed in the test concentrationsof 6.25, 12.5, 25, 50 and 100mg/L respectively.

Based on the results of range finding test, A limit test was conducted with a limit test concentration of 100 mg/L to assess the growth inhibition of algae in terms of growth rate and yield. Six replicates were used for both control and a limit test concentration. The control group was used with OECD medium without test item.

During the limit test period, all the flasks were incubated in the orbital Rotary shaker under controlled temperature, light and agitation.The pH of the control at the start and at termination of the study was 8.1 respectively, and therefore did not vary more than 1.5 units during the study. The pH of the test concentrations ranged between 7.5 to 8.1 at the beginning of the test and 7.4 to 8.0 at test termination. The room temperature during the limit test ranged from23.0 to 25.0°C. The temperature of the test concentrations ranged between 22°C to 23°C at the beginning of the test and at test termination. The mean intensity of light ranged from 6540 to 6850 Lux and the % CV ranged from 4.11% to 6.55%, which is proved that the light intensity is maintained within ±15% from the average light intensity.

No significant changes in the appearance of algae cells were observed in control and in the test concentrations during 72 hours test period. At the end of 72 hour observation, 2.41% in terms of inhibition of growth rate and 11.03% in terms of inhibition of yield was observed in the test concentration of 100 mg/L respectively.

 

The test item available in the test medium (natural water) was determined by a validated HPLC system. The test item concentration ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-idein the OECD medium at the initiation (0 hour) 96.55% and after 72 hours 96.56 % of the nominal test concentrations. As the measured concentrations were within 80 to 120% of the nominal concentration during the exposure period.

 

Based on the results of this study, the ErC50(growth rate) value for72 hours ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-idewas found to begreater than 100 mg/LThe LOEC and NOEC based on the inhibition of growth rate and yield was found to be greater than or equal to 100 mg/L. The results observed in the present study meets all the validity criteria as per OECD 201 Test guideline. Based on the outcomes the test chemical cannot be classifed as per CLP classification criteria.

Toxicity to microorganisms:

1. NOECs was considered to be 1000 mg/L when Activated Sludge was treated with test chemical for 10 minutes.

2. Based on the 17 hrs exposure study of bacteria with the test chemical, the EC50 was determine to be 7000 mg/l on the basis of growth rate inhibition.

3. Based on the growth rate inhibition of bacteria by the test chemical for 17 hrs, the EC50 was 3800 mg/l.

4. Inhibition concentration IC50 to 50% of Tetrahymena pyriformis when expeosed to test chemical for 60 h is 387.7 mg/L.

Additional information

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:

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 test solution was prepared by dissolving 100 mg, 200 mg, 400 mg, 800 mg & 400 mg of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous stirring for achieving test concentrations of 25 mg/L, 50 mg/L, 100 mg/L, 200 mg/L & 400 mg/L, respectively and Zebra Fish Danio rerio were 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 > 400 mg/l . Based on the LC50, it can be consider that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Long term toxicity to fish:

Using the EPI Suite ECOSAR, the long term toxicity on fish was predicted for test substance. On the basis of no effects observed in a freshwater system, the no observed effect concentration (NOEC) value for the substance is estimated to be 307.146 mg/l for fish for 28 d duration. Based on this value, it can be concluded that the test chemical can be considered as non-toxic to fish and can be considered to be not classified as per the CLP classification criteria.

 

Short term toxicity to aquatic invertebrates:

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

The objective of this study was conducted to evaluate the Acute toxicity of test chemical  to the Daphnia sp., (Daphnia magna). The study was performed in compliance with following regulatory guideline: OECD Guideline for Testing of chemicals OECD NO. 202, Adopted by the Council on 13 April 2004, Daphnia sp. Acute Immobilization Test.

Solubility of test item was performed by dissolving in the natural water (ground water) at 254 mg/L. Based on the solubility test, a vehicle was selected as a natural water for the test in the study.

Stability of the test item in natural water determined by analyzing the test concentrations of 1 and 100.0 mg/L at 0 hour, 24 hour and 48 hour showed that the test item concentration remained 80% to 120%(96.81 to 98.34 %) with respect to initial measured concentration and hence the dose verification for limit test was performed at the beginning and at the termination of the test.

The brood daphnids were acclimatized 48 hours prior to the test item exposure in dilution water. Less than 24 hours old daphnids were collected from the acclimatized gravid females and exposed to the test item. After exposure on day 0, daphnids were observed for Immobilization at 24 and 48 hours.

Range finding test was conducted with test concentration of 6.25, 12.5, 25, 50 and 100 mg/L along with a control group without test item by static method. Each concentration contained two replicates and 5(five) Daphnids per replicate. Test item was formulated in natural water. The treated Daphnids were maintained in a condition. No immobilization (percent) and any abnormal behaviour observed in control group and in all the tested concentrations of 6.25, 12.5, 25, 50 and 100 mg/L for a period of 48 hours.

Based on the results of range finding test, the limit test was conducted with a test concentration of 100 mg/L along with a control group without test item by static method. A limit test concentration contained four replicates and 5(five) Daphnids per replicate. Test item was formulated in natural water. The treated Daphnids were maintained in a test condition. No immobilization (percent) and any abnormal behaviour observed in control group and a limit tested concentration of 100 mg/L for a period of 48 hours.

During thelimit test period, all the beakers were incubated in the roomunder test condtion.The pH of the control at the start and at termination of the study was 6.8 and therefore did not vary more than 1.5 units during the study. The pH of the limit test concentrations was 6.9 at the beginning of the test and 7.0 at test termination. The room temperature was between 19.0°C and 20.9°C. The temperature of the control and a limit test concentrationat the beginning of the test and at test termination was 20°C and 21°C. The Dissolved oxygen of the control at the start and at termination of the study was 8.2 and 5.2 mg/L. The Dissolved oxygen of the limit test concentration was 8.1 at the beginning of the test and 4.9 mg/L at test termination. The mean intensity of light ranged from 1425 to 1443 Lux.

The test item available in the test medium (natural water) was determined by a validated HPLC system. The test item concentration of test chemical in the test medium at the initiation (0 hour) 97.12% and after 48 hours 96.40 % of the nominal test concentrations. As the measured concentration was within 80 to 120% of the nominal concentration during the exposure period.

Based on the results of this study, the EC50value for 48 hours of Sodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-ide was found to be greater than 100 mg/L.The results observed in the present study meets all the validity criteria as per OECD 202 Test guideline. Based on the outcomes test chemcial cannot be classified

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 202 (Daphnia sp. Acute Immobilisation Test) in a static system for the total exposure period of 48 hrs. The solution of white crystalline powder 100 mg/l was prepared by dissolving the substance in reconstituted test water. 100 mg/l concentration 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 > 100 mg/L on the basis of mobility inhibition effects in a 48 hour study. After the exposure period of 48 hrs, only 8% inhibition were observed at 100 mg/l. Based on the EC50 value, substance is likely to be non-hazardous to aquatic invertebrate and cannot classified as per the CLP classification criteria.

 

Above study was supported by the second supporting study. Acute Immobilization Study of test chemical was performed on Daphnia magna in a Semi-Static System for 48 hrs. Test performed according to the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test). The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 100 mg of the test substance in 100 ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively. And test Daphnia magna were exposed to these concentration for 48 hours. Study consider to be valid as it performs according to the guideline. 1. In the control, including the control containing the solubilizing agent, not more that 10 percent of the daphnids should have been immobilized as per the guideline and the same results were obtain in the test. 2. The dissolved oxygen concentration at the end of the test should be 3 mg/l in control and test vessels. The median lethal concentration (EC50) for test chemical on Daphnia magna in a 48 hours study on the basis of immobilization effect was determine to be > 100 mg/l. Thus, on the basis of this EC50 value and according to CLP criteria for aquatic classification of the substance, it is concluded that the substance does not exhibit short term toxicity to Daphnia and thus not classified as per the CLP classification criteria.

Thus based on the above studies, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

Long term toxicity to aquatic invertebrates:

 

Summarized result for the toxicity of test chemical on the growth and mobility of daphnia magna were determine and mention as below:

 

Based on the prediction done using the EPI Suite ECOSAR, the long term toxicity on daphnia magna was predicted for test substance. On the basis of effects observed in a freshwater system, the no observed effect concentration (NOEC) value for the substance is estimated to be 119.839 mg/l for daphnia magna for 21 day duration. On the basis of this value, it can be concluded that the test chemical can be considered as non-toxic to daphnia magna and can be considered to be not classified as per the CLP classification criteria.

 

 

Similar study 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 data and results, chemical consider to be nontoxic to the aquatic invertebrates and not classified as per the CLP classification criteria.

 

Toxicity to algae and cyanobacteria:

Various short term studies available for the test 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:

 

The study was conducted to assess the effects ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-ideon the growth of green Algae,Pseudokirchneriella subcapitataaccording to the OECD Test Guideline 201, ‘Freshwater Algae and Cyanobacteria, Growth Inhibition Test’ (March, 2006) and Council Regulation (EC) No. 440/2008, Annex Part C.3: ‘Algal Inhibition Test’.

The test concentrations were prepared in OECD TG 201 media by dilution of stock and transferred 100 ml of each test solution into 250 ml Erlenmeyer flasks. The control and treatment flasks were inoculated withPseudokirchneriella subcapitatapre-cultured for 3 days and tested at an initial cell density of 1 × 104cells per ml, incubated under test condition for 72 hours. The cells were counted using an Improved Neubaur’s Haemocytometer under illumination of the microscope at 24, 48 and 72 hour after inoculation.

Weighed 25.5 mg of the test item in a 100 ml volumetric flask dissolved and made up to the mark usingOECD mediumand the resulting concentration was 255 mg/L coded as stock.Based on the solubility test, a vehicle was selected as a OECD medium for the test in the study.

Stability of the test item in OECD medium determined by analyzing the test concentrations of 1 and 100.0 mg/L at 0 hour, 24 hour, 48 hour and 72 hour showed that the test item concentration remained 80% to 120% (95.06 to 97.4%) with respect to initial measured concentration and hence the dose verification for limit test was performed at the beginning and at the termination of the test.

A range finding test was conducted with test item concentrations of 6.25, 12.5, 25, 50 and 100 mg/L with three replicates per test item concentration and six replicates for the control to assess the growth inhibition of alga in terms of growth rate and yield. The control group was used with OECD medium without test item.No significant changes in the appearance of algae cells were observed in control and in the test concentrations during 72 hours test period. At the end of 72 hour observation,0.48%, 0.61%, 1.13%, 2.03 % and 2.65% in terms of inhibition of growth rate and 2.32%, 2.89%, 5.25%, 9.16% and 11.77% in terms ofinhibition of yield was observed in the test concentrationsof 6.25, 12.5, 25, 50 and 100mg/L respectively.

Based on the results of range finding test, A limit test was conducted with a limit test concentration of 100 mg/L to assess the growth inhibition of algae in terms of growth rate and yield. Six replicates were used for both control and a limit test concentration. The control group was used with OECD medium without test item.

During the limit test period, all the flasks were incubated in the orbital Rotary shaker under controlled temperature, light and agitation.The pH of the control at the start and at termination of the study was 8.1 respectively, and therefore did not vary more than 1.5 units during the study. The pH of the test concentrations ranged between 7.5 to 8.1 at the beginning of the test and 7.4 to 8.0 at test termination. The room temperature during the limit test ranged from23.0 to 25.0°C. The temperature of the test concentrations ranged between 22°C to 23°C at the beginning of the test and at test termination. The mean intensity of light ranged from 6540 to 6850 Lux and the % CV ranged from 4.11% to 6.55%, which is proved that the light intensity is maintained within ±15% from the average light intensity.

No significant changes in the appearance of algae cells were observed in control and in the test concentrations during 72 hours test period. At the end of 72 hour observation, 2.41% in terms of inhibition of growth rate and 11.03% in terms of inhibition of yield was observed in the test concentration of 100 mg/L respectively.

 

The test item available in the test medium (natural water) was determined by a validated HPLC system. The test item concentration ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-idein the OECD medium at the initiation (0 hour) 96.55% and after 72 hours 96.56 % of the nominal test concentrations. As the measured concentrations were within 80 to 120% of the nominal concentration during the exposure period.

 

Based on the results of this study, the ErC50(growth rate) value for72 hours ofSodium 1,1,3-trioxo-2,3-dihydro-1H-11ambda6, 2-benzothiazol-2-idewas found to begreater than 100 mg/LThe LOEC and NOEC based on the inhibition of growth rate and yield was found to be greater than or equal to 100 mg/L. The results observed in the present study meets all the validity criteria as per OECD 201 Test guideline. Based on the outcomes the test chemical cannot be classifed as per CLP classification criteria.

Aim of this study was to evaluate the nature of chemical 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 solution of white crystalline powder 100 mg/l was prepared by dissolving the substance in OECD growth medium. Test conducted at limit concentration of 100 mg/l. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, The differences in means of control and sample were estimated by the t-test for independent groups at a 95 % confidence level, all individual replicates were used (STATISTICA CZ – data analysis software system, version 9.0, StatSoft, Inc.). Statistically significant differences are for p < 0.05. Based on the no growth rate inhibition of algae Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) due to the exposure of chemical the EC0 was determine to be 100 mg/l after the exposure period of 72 hrs. Based on the EC0 value, substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

 

Above study was supported by the second experimental supporting study. The study was designed to assess the toxic effects of the test compound on the green alga Chlorella vulgaris. Test was conducted in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test). Test was carried out in 100mL conical flasks which were carefully autoclaved and sterilized. The test solution in each of these test vessels was kept constant which is 60 ml so that a sufficient amount of head space was left. The test solution was prepared in aseptic condition. The test item was prepared by adding 50 mg of test item in 250ml of BBM to get the final concentration of 200mg/L. This stock solution was kept for stirring 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 remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 10000 cells/ml. Care was taken to have a homogeneous solution for the experiment. For the assessment of algal growth, the test was conducted in replicates. The control flask was maintained in triplicates as recommended in the OECD guideline and the test concentration were selected in geometric series which were maintained in duplicates. To obtain a quantitative concentration- response relationship by regression analysis, a linearizing transformation of the response data into probit was performed. Using the same, effective concentration (EC) were determined. Algal growth was calculated daily by counting the cells microscopically with the help of haemocytometer. For microscopic observations the cultures were observed daily with the help of a microscope to verify a normal and healthy appearance of the algal culture and also to observe any abnormal appearance of the algae (as may be caused by the exposure of the test item). Apart from this, the cell count of each test vessel was also noted with the help of a microscope and haemocytometer. By spectrophotometer the absorbance values of each test vessel and control vessel was noted at 680nm.The BBM was taken as blank for both control and test vessels. The absorbance value of each vessel was in line with the average specific growth rate. According to the test validity criteria the following criteria are met in this test: Firstly As per OECD 201, the biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72 hr test period. This corresponds to a specific growth rate of 0.92 per day. Thus, the observed specific growth rate in the control cultures during the experiment was 1.501 per day. Secondaly The mean coefficient of variation for section by section specific growth rates (days 0-1, 1-2 & 2-3, for 72 hr tests) in the control cultures must not exceed 35%. Thus, the observed mean coefficient of variation in the control cultures during the experiment was 13.025%. Thirdly the coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 10%. Thus, the observed coefficient of variation of average specific growth rates during the experiment in control cultures was 1.995 %. Hence, the test is considered valid as per OECD guideline, 201. Based on the growth rate inhibition of green alga Chlorella vulgaris by the test chemical, EC50 was observed experimentally was >200 mg/l and the EC30 was determine to be 265.984 mg/l graphically and through probit analysis. Based on the EC50, it can be concluded that the chemical was nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

Thus based on the above data and results from experimental studies, chemical consider to be nontoxic to the aquatic algae and cyanobacteria and thus not classified as per the CLP classification criteria.

 

Toxicity to microorganisms:

Various 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 growth and other activity of microorganisms. The studies are as mentioned below:

In a Respiration Inhibition Test, Activated Sludge treated with test chemical in the synthetic feed composed of easily available nutrients for 10 min. no effect were observed on respiration rate of treated Activated Sludge as compared to control. Therefore, NOECs was considered to be 1000 mg/L when Activated Sludge were treated with test chemical.

First study supported by second study. Study was carried out to evaluate the nature of chemical on the bacterial growth. Study was conducted for 17 hrs in which unadapted biological waste water treatment plants were exposed with chemical. Based on the 17 hrs exposure study of bacteria with the test chemical, the EC50 was determine to be 7000 mg/l on the basis of growth rate inhibition.

Aim of this next study was to determine the nature of test chemical on the growth of bacteria. Study was conducted for 17 hrs in which unadapted biological waste water treatment plants were exposed with chemical. Based on the growth rate inhibition of bacteria by the test chemical for 17 hrs, the EC50 was 3800 mg/l. Thus the chemical was not highly toxic to the growth of bacteria.

Similar study was carried out to detrmine the effects of test chemical on micro-orgnaisms test was carried out under static condition for 60 hours. Decreasing trend of Population growth rate was measured during the test.Inhibition concentration IC50 to 50% of Tetrahymena pyriformis when expeosed to test chemical for 60 h was determine to be 387.7 mg/L.

Thus based on the overall data for the test chemical, it was consider that the chemical was not toxic to microorganisms.