Potassium hydrogen phthalate

Endpoint summary

Description of key information

Short-term toxicity to fish:

Study was conducted to access the effect of test chemical Hydrogen potassium phthalate 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 400 mg of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous one hour stirring for achieving test concentrations of 100mg/L, respectively. Potable water (passed through reverse osmosis system) was used 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 Hydrogen potassium phthalate to various nominal test concentrations, LC50 was determine to be > 100 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.

Short term toxicity to aquatic inverbebrates:

Aim of this study was to assess the short term toxicity of Hydrogen potassium phthalate 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 solution 100 mg/l was prepared by dissolving white powder in reconstituted water. Limit test were performed at 100 mg/l 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. After the exposure of test chemical Hydrogen potassium phthalate for 48 hrs with Daphnia magna, no effect were observed at the limit concentration of 100 mg/l. 0 % inhibition were observed at 100 mg/l. Thus on that basis it was consider that the EC50 was > 100 mg/l. Thus based on the above observations, it was consider that the chemical was nontoxic and non-hazardous and can be consider to be not classified as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria:

Study was conducted 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 stock solution 220 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentrations 0, 77, 100, 130, 170 and 220 mg/l were used in the study. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration ErC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. The median effective concentration (ErC50) for the test substance Hydrogen potassium phthalate, in algae was determined to be 329.5 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the ErC50 value, indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

Toxicity to microorganisms:

EC50 for Potassium hydrogen phthalate was found to be 498.52 and 997 mg/l when tested on Marine Dinoflagellate Gymnodinium breve for 96 hours.

Additional information

Summarized result of toxicity of the chemicalhydrogen potassium phthalate (CAS no. 877-24-7) on the growth of fishes, aquatic invertebrates and algae and microorganisms was studied by considering and collecting the data from various databases for target chemical. The studies are as follows:  

 

Short term toxicity to fish:

Based on the experimental data from various database for the target chemical and read across chemicals study have been reviewed to determine the mode of action ofhydrogen potassium phthalate (Cas no. 877-24-7) on the mortality rate and behavior of fish. The studies are as mentioned below:

 

In the first key study from experimental report. Study was conducted to access the effect of test chemical Hydrogen potassium phthalate 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 400 mg of the test substance in 4 liters of potable water (passed through reverse osmosis system) with continuous one hour stirring for achieving test concentrations of 100mg/L, respectively. Potable water (passed through reverse osmosis system) was used 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 Hydrogen potassium phthalate to various nominal test concentrations, LC50 was determine to be > 100 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.

 

First study was supported by the second study for peer reviewed journal. Acute fish toxicity study was conducted on Gambusia affinis (Western Mosquitofish) for exposure period of 96 hrs. with test temperature 19 to 21 deg C and pH 3.8 to 7.0, Alkalinity:100 ppm MO in static freshwater condition. Concentrations used as 10,18,32,56 and 100 mg/l if death not observed then same series was used between 100 and 1000 mg/l again if no death observed continue with 1000 and 10000mg/l. During experiment the lethal concentration (LC50) was observed to be 180 mg/l on the basis of mortality effect. Thus based on the experimental result it is concluded that the test chemical was nonhazardous to fish.

 

Thus on the basis of overall studies chemicalhydrogen potassium phthalate (CAS no. 877-24-7)was consider as nontoxic to fishes and not classified as per the CLP classification criteria.

 

Short term toxicity to aquatic invertebrates:

Aim of this study was to assess the short term toxicity of Hydrogen potassium phthalate 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 solution 100 mg/l was prepared by dissolving white powder in reconstituted water. Limit test were performed at 100 mg/l 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. After the exposure of test chemical Hydrogen potassium phthalate for 48 hrs with Daphnia magna, no effect were observed at the limit concentration of 100 mg/l. 0 % inhibition were observed at 100 mg/l. Thus on that basis it was consider that the EC50 was > 100 mg/l. Thus based on the above observations, it was consider that the chemical was nontoxic and non-hazardous and can be consider to be not classified as per the CLP classification criteria.

 

Short term toxicity to aquatic algae and cyanobacteria:

Summarized result for the toxicity of test chemicalhydrogen potassium phthalate (CAS no. 877-24-7) on the growth of aquatic algae and cyanobacteria are as follows:

 

In the first experimental report, study was conducted 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 stock solution 220 mg/l was prepared by dissolving white powder in OECD growth medium. Test solutions of required concentration as were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture. Various concentrations 0, 77, 100, 130, 170 and 220 mg/l were used in the study. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration ErC50 was calculated using nonlinear regression by the software Prism 4.0. Effect on the growth of algae was determine after an exposure period of 72 hrs. The median effective concentration (ErC50) for the test substance Hydrogen potassium phthalate, in algae was determined to be 329.5 mg/L on the basis of growth rate inhibition effects in a 72 hour study. Based on the ErC50 value, indicates that the substance is likely to be non-hazardous to aquatic algae and cannot be classified as per the CLP classification criteria.

 

First study was supported by the second study from experimental report. The study was designed to assess the toxic effects of the test compound Hydrogen potassium phthalate on the green alga Chlorella vulgaris. Test was conducted in compliance with the OECD guideline 201 (Alga, Growth Inhibition Test). The test solution was prepared in aseptic condition. The test item Potassium hydrogen phthalate 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 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 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 hemocytometer. 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 hemocytometer. 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. 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 0.333 per day. 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 21.6%. 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 3.94%. Hence, the test is considered valid as per OECD guideline, 201. After 72 hours of exposure to test item Hydrogen potassium phthalate to various nominal test concentrations, EC50 was determine to be 19.885 mg/l graphically and through probit analysis. Based on the EC50, 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. But as the chemical was readily biodegradable in water thus does not exist for long time in water. Based on readily biodegradable criteria, chemical consider to be nontoxic and not classified as per the CLP classification criteria.

 

 

Similarly in the third study from peer reviewed journal short term toxicity to algae study was carried out for 96 hrs. The study was based on the effects of the test compound on algae in a static fresh water system. 1% solution of test chemical was prepared in distilled water, i.e. 1.0 g of the compound in 100 ml of distilled water. Test chemical conc. used for the study were 1, 10, 20, 50, 100, 200, 500 and 1000 mg/l, respectively (nominal concentrations). Gymnodinium breve was used as a test organism. Cultures of Gymnodinium breve were grown in an artificial sea water medium--NH-15 and were transferred 14 days prior to use so that they would be in an active logarithmic growth phase. Test portions were placed in a single row in test tube racks which were placed 2 inches from 40-watt, cool-white fluorescent lights (incident light ca. 1000 foot-candles) in a 25°C, constant temperature room. Special care was taken to insure uniform light on test portions to avoid variability of relative chlorophyll a values. Microscopic examinations and relative chlorophyll a measurements were carried out as soon as the portions were set up, and 24, 48, 72 and 96 hours thereafter. Initial counts of the culture population level were also carried out prior to setting up the test portions and counts were made of each test portion after 96 hours. Based on the effect of test chemical on the population of the test organism Gymnodinium breve, the 96 hrs NOEC and LOEC value was determined to be 200 and 500 & 1000 mg/l, respectively.

 

Thus based on the above both studies, chemicalhydrogen potassium phthalate (CAS no. 877-24-7) was consider to be nontoxic and not classified as per the CLP classification criteria.

 

Toxicity to microorganisms:

In a study of toxicity of Phthalates to the Marine Dinoflagellate Gymnodinium breve the effect of Potassium hydrogen phthalate was evaluated. The test substance was tested in a concentration of 0,1,10, 20, 50, 100, 200, 500, 1000 and 1000 ppm. The results show Median growth when concentration of test material (ppm) versus the growth rate (linear axis of graph), expressed as a percentage of the growth of a "no-add" control at 498.52 and 997 mg/l. Therefore, EC50 of Potassium hydrogen phthalate was considered to be be 498.52 and 997 mg/l when tested on Marine Dinoflagellate Gymnodinium breve for 96 hours.