Potassium iodate

Endpoint summary

Description of key information

Short term toxicity to fish:

1: Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for test material on Zebra fish (Danio rerio) was determined to be 100 mg/L by observing the mortality.

2: Based on nominal concentrations, the median lethal concentration LC-50 (96 h) for test chemical on the mortality of fishe Danio rerio was observed to be >100 mg/L.

Thus based on the above effects, chemical consider to be nontoxic and not classified.

Long term toxicity to fish:

Using the EPI Suite, 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 6.17e+006 mg/l for fish for 28 d duration.

 

Short term toxicity to aquatic invertebrate:

1: Based on nominal concentrations, experimental median effective Concentrations [EC-50 (48 h)] for test chemical on freshwater daphnia magna was determine to be 100 mg/L.

2: The lethal concentration (LC50) value of test chemical on aquatic invertebrates (Dreissena polymorpha) in a 24 hrs study by observing effect on mortality was determine to be 226 mg/L.

Long term toxicity to aquatic invertebrate:

1. After the exposure of test chemical with daphnia magna for 21 days effect were not observed at the concentration 14 mg/l. Thus NOEC was determine to be 14 mg/l. By considering this NOEC value it is concluded that test chemical is nontoxic to aquatic invertebrates and cannot be classified as per the CLP regulation.  

2. After the exposure of test chemical with daphnia magna for 21 days no effects were observed on reproduction rate and appearance of 1st offspring at the concentration 91 mg/l.

Thus based on the overall studies, it was concluded that the test chemical was nontoxic to aquatic invertebrate and it cannot be classified as per the CLP classification criteria.

Toxicity to algae and cyanobacteria:

1: Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. study on growth effect was determine to be 356.8 mg/L.Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

2: Minimum Inhibitory Concentration (MIC100) of test chemical in green algae (Chlorella sp.) in a 10 days study on growth effect was observed to be 696.2 ± 9.4 mg/L.

3: Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Cryptomonas sp.) in a 10 days. study on growth effect was determine to be 475.9 ± 10.3 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that the test chemical does not exhibit toxicity to green algae (Cryptomonas sp).

Toxicity to microorganisms:

The test chemical  is not likely to be toxic to microorganisms atleast in the dose range of 358-500 mg/l.

Additional information

Short term toxicity to fish:

 

Summarized result for the toxicity of test chemical including structurally and functionally similar read across chemical on the mortality of fish were reviewed and mention below:

 

This study was designed to assess the toxic effects of the test compound on the Zebra fish (Danio rerio). Test was conducted in compliance with the OECD guideline 203. 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. After the completion of 1 hour stirring test solution was prepared for achieving the test concentration of 6.25 mg/L, 12.5 mg/L, 25 mg/L, 50 mg/L & 100 mg/L, respectively. Study conducted under the static system for 96 hrs. Test animal was collected from Anytime Pet, Jariphataka, Nagpur. 8 fishes exposed to the test concentration. Aeration in test vessels was provided 1 day before the start of experiment. After the exposure of chemical (mortality, visible symptoms, pH, Temperature, dissolved oxygen content) were recorded after 24 hours, 48 hours, 72 hours and 96 hours of the start of the experiment. Based on nominal concentrations, experimental median lethal Concentrations [LC-50 (96 h)] for Potassium nitrite on Zebra fish (Danio rerio) was determined to be 100 mg/L by observing the mortality. As the effect were observed at borderline 100 mg/l, so we cannot classify the chemical as toxic.

 

Above study was supported by the second study from experimental report. This study was designed to assess the acute toxic effects of the test compound on the Zebra fish (Danio rerio). Bowl aquaria containing 10 liters of deionized water were loaded with 8 fishes each. A static procedure was used for the study and it was conducted in compliance with the OECD Guideline 203 (Fish, Acute Toxicity Test). The test solution was prepared by dissolving 1g of the test substance in10 liters deionized water with continuous stirring for achieving the test concentration of 100 mg/L, respectively. The limit test at 100 mg/L was conducted and it was observed that the LC-50 is greater than this concentration. Observations (mortality, visible symptoms, pH, Temperature, dissolved oxygen content) were recorded after 24 hours, 48 hours, 72 hours and 96 hours of the start of the experiment. The test vessels used were all glass bowl aquaria of 12” each. In a 96 h study for test chemical on Danio rerio, at a test concentration of 100 mg/L, the fishes were found to be freely swimming in the bowl aquaria without showing any abnormal symptoms. No mortalities were observed at the test concentration of 100 mg/l. No mortalities were found in the control aquaria. The LC0 (96 hours) was observed at 100 mg/L (highest concentration at which no mortality was observed). LC50 (96 hours) was > 100mg/L.

 

Thus based on the above effects, chemical consider to be nontoxic and not classified.

 

 

 

Long term toxicity to fish:

Using the EPI Suite, 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 6.17e+006 mg/l for fish for 28 d duration.

 

Short term toxicity to aquatic invertebrate:

Various studies for the test chemical and structurally and functionally similar read across chemical were reviewed and summarized for the determination of chemical effect on the mobility of test organisms aquatic invertebrates which are as follows:

 

The study was designed to assess the toxic effects of the test compound on the test Daphnids. Beaker containing 20ml of media with 10 Daphinds. A semi-static procedure was used for the study and it was conducted in compliance with the OECD guideline 202. The test substance was soluble in water. Therefore, the test solution was prepared by dissolving 2 mg of the test substance in 20 ml of ADaM’s media. Achieving test concentrations of 100 mg/L, respectively. The test concentrations selected for the study was 100 mg/L. The test vessels used were all glass beaker having the water capacity of 25ml, in each vessel 10 daphnia were incorporated. Observations (immobility, pH, Temperature, dissolved oxygen content) were recorded after 24 and 48hours of the start of the experiment. Based on nominal concentrations, experimental median effective Concentrations [EC-50 (48 h)] for test chemical on freshwater daphnia magna was determine to be 100 mg/L. This value indicates that the substance is likely to be non hazardous to aquatic invertebrate and cannot be classified as per the CLP criteria.

 

Similar study was conducted to determine the effect of test chemical on Dreissena polymorpha. Test conducted under the static system on 1.5-2.0 cm old freshwater Dreissena polymorpha. 24 hrs of exposure period were provided. The lethal concentration (LC50) value of test chemical on aquatic invertebrates (Dreissena polymorpha) in a 24 hrs study by observing effect on mortality was determine to be 226 mg/L. Based on the LC50 value, chemical consider to be nontoxic and can be consider to be not classified as per the CLP classification criteria.

 

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

 

Long term toxicity to aquatic invertebrate:

 

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

 

In the first study (from peer reviewed journal) toxicity was measured. Aim of this study is to determine the effect of test chemical on the 24 hrs old Daphnia Magna by providing the exposure period of 21 days. Effect were measured on the basis of reproduction rate inhibition. Test conducted in Equivalent to OECD 211. This experiment was performed on 24 hrs old Daphnia magna (IRCHA strain) and synthetic fresh water was used as medium in this medium The amount of calcium and magnesium ions was 2.5mmol/L. Before preparing the dilution series the test chemical was fully dissolved in water using magnetic stirrers. From the stock solution of the substance to be tested, graduated dilutions with dilution water were produced in the concentration range in which effects were to be expected in accordance with the results from the acute 24 h Daphnia test. Four parallel test vessels per concentration level and the controls comprising at least four vessels were filled with 24 h-old Daphnia 1 animal/50 ml and this meant 20 test animals (1 litre) per concentration level and COD of 15-20 mg/L. The semi-static procedure was used in this experiment the parent animals in the test and control vessels had to be pipetted 3 times a week into freshly prepared test and control media in each case at the corresponding concentration level. Then, the pH value and the oxygen concentration were measured in two test vessels per concentration level and the photo period 9 hrs light and 16 hrs dark. The validity criteria were reproduction rate per parent animal after 21 days, in the case of the test preparation in the beakers, was 88.8 offspring (SD = 13.1; coefficient of variation = 14.8%), The "parent animal mortality" after 21 days was 7.1% in the case of the test preparation in beakers and 9.1% in bottles, the pH always remained in the neutral to subalkaline range. After the exposure of test chemical with daphnia magna for 21 days effect were not observed at the concentration 14 mg/l. Thus NOEC was determine to be 14 mg/l. By considering this NOEC value it is concluded that test chemical is nontoxic to aquatic invertebrates and cannot be classified as per the CLP regulation. 

 

Similarly the first study was supported by the second study from peer reviewed journal. Aim of this study was to determine the effect of test chemical on the 24 hrs old Daphnia Magna by providing the exposure period of 21 days. Effect were measured on the basis of reproduction rate inhibition and appearance of 1st offspring. Test conducted in Equivalent to OECD 211. This experiment was performed on 24 hrs old Daphnia magna (IRCHA strain) and synthetic fresh water was used as medium in this medium The amount of calcium and magnesium ions was 2.5mmol/L. Before preparing the dilution series the test chemical was fully dissolved in water using magnetic stirrers. From the stock solution of the substance to be tested, graduated dilutions with dilution water were produced in the concentration range in which effects were to be expected in accordance with the results from the acute 24 h Daphnia test. Four parallel test vessels per concentration level and the controls comprising at least four vessels were filled with 24 h-old Daphnia 1 animal/50 ml and this meant 20 test animals (1 litre) per concentration level and COD of 15-20 mg/L. The semi-static procedure was used in this experiment the parent animals in the test and control vessels had to be pipetted 3 times a week into freshly prepared test and control media in each case at the corresponding concentration level. Then, the pH value and the oxygen concentration were measured in two test vessels per concentration level and the photo period 9 hrs light and 16 hrs dark. The validity criteria were reproduction rate per parent animal after 21 days, in the case of the test preparation in the beakers, was 88.8 offspring (SD = 13.1; coefficient of variation = 14.8%), The "parent animal mortality" after 21 days was 7.1% in the case of the test preparation in beakers and 9.1% in bottles, the pH always remained in the neutral to subalkaline range. After the exposure of test chemical with daphnia magna for 21 days no effects were observed on reproduction rate and appearance of 1st offspring at the concentration 91 mg/l. By considering this NOEC value it is concluded that test chemical is nontoxic to aquatic invertebrates and cannot be classified as per the CLP regulation. 

 

Thus based on the overall studies, it was concluded that the test chemical was nontoxic to aquatic invertebrate and it cannot be classified as per the CLP classification criteria.

 

Toxicity to algae and cyanobacteria:

 

Summarized result for the toxicity of test chemical and structurally and functionally similar read across chemicals on the growth of algae were studied and reviewed. The details are as mention below: 

 

To evaluate toxicity of test chemical on the growth of Dunaliella salina. Saltwater Dunaliella salina were used as a test organism which exposed for the 10 days of incubation. Serial concentrations of test chemical were supplemented into the modified medium for the culture of Dunaliella salina. The inocula, each containing 3 × 10(4) alga cells, were added to 10mL of the corresponding media and incubated in an oscillator shaker at a rate of 150 rpm under light irradiation of 81.04μmolm−2 s−1 and a 12 h/12 h light/dark cycle. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Dunaliella salina) in a 10 days. Study on growth effect was determine to be 356.8 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that test chemical does not exhibit toxicity to green algae (Dunaliella salina).

 

 

First study was supported by the second study from peer reviewed journal. In this study the effects of chemical on the growth and metabolite accumulation of Chlorella sp. were investigated to assess its possible application to the mass culture of the two diatoms in open environment, extensive systems. Test conducted under the static system for 10 days. Brackish water Chlorella sp. maintain under the proper conditions of temperature and pH. Serial concentrations of test chemical were supplemented into the f/2 medium for Chlorella sp. At concentrations >700 mg/l, the growth of Chlorella sp. was inhibited. Minimum Inhibitory Concentration (MIC100) of test chemical in green algae (Chlorella sp.) in a 10 days study on growth effect was observed to be 696.2 ± 9.4 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that the test chemical does not exhibit toxicity to green algae (Chlorella sp.) and thus not classified.

 

 

Similarly in the third study aim of this study was to determine the effect of test chemical on the growth of Cryptomonas sp. Test conducted under the static system for the total exposure period of 10 days. Minimum Inhibitory Concentration (MIC100) value of test chemical in green algae (Cryptomonas sp.) in a 10 days study on growth effect was determine to be 475.9 ± 10.3 mg/L. Thus considering CLP Criteria for aquatic classification of the substance, it is concluded that the test chemical does not exhibit toxicity to green algae (Cryptomonas sp) and thus not classified as per the classification criteria.

 

Thus based on the above data from various peer reviewed journals, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

Toxicity to microorganisms:

 

Data available for the test chemical and structurally and functionally similar read across chemicals has been reviewed to determine the short term toxicity on micro-organisms for the test chemical .The studies are as mentioned below:

 

In the first study Minimum Inhibitory Concentration (MIC100) value of test chemical in microorganism (Staphylococcus aureus) in a 24hrs. Study on growth effect was found to be 358.3 ± 17.1 mg/L. It is concluded that test chemical does not exhibit toxicity to microorganism (Staphylococcus aureus).

 

Another study was evaluated for its toxicity on microorganism the test chemical was used to evaluate minimum inhibition concentration on the test organism Bacillus subtilis after inoculation of test substance for 24 hrs the effect concentration was observed to be 500 mg/l. Based on the above concentrations it can be concluded that test substance is nontoxic to microorganisms.

 

The test chemical is not likely to be toxic to microorganism’s atleast in the dose range of 358-500 mg/l.