2-furoic acid

Endpoint summary

Description of key information

Short term toxicity to fish

Short term toxicity to fish was conducted for 96 hrs for assessing the effect of test chemical (Study report). The test was performed in accordance to OECD guideline No. 203 “Fish Acute Toxicity Test”. Zebra fish (Danio rerio) of average weight 0.045 g and average length of 1.4 cm was used as a test organism for the study. Test fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration. During the housing period, test fishes were fed once daily with standard brand fed. The test conditions during the housing of the test organisms were oxygen content of 7.6 mg/l, pH 7.5, water temperature 23.9°C and under a photoperiod of 16:8 hr light: dark conditions, respectively. Test was performed using test chemical concentrations of 0, 3.125 mg/l, 6.25 mg/l, 12.5 mg/l, 25 mg/l and 50 mg/l, respectively. Total 8 fishes were exposed to test chemical in a 5 lit bowl aquaria containing 4 liters of potable water. The test vessels were placed in a room at a temperature of 23.9°C, pH 7.2, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions, respectively. Aeration in test vessels was provided 1 day before the start of the experiment. No mortalities were observed in the control. Test fishes were moving slowly as compared to control. On the basis of effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be 50 mg/l. Thus, based on the LC50 value, test chemical was considered as toxic to aquatic fishes. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be not classified as per the CLP classification criteria.

Short term toxicity to aquatic invertebrates

An acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical on Daphnia magna (Study report). The test was performed in accordance to OECD guideline No. 202“Daphnia sp.,Acute Immobilization Test”. The test solution was prepared by dissolving 100mg of test chemical in 100ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively. Test chemical concentrations used for the study were 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively. Study was performed using 10 daphnids in a static system. Total 10 Daphnids/conc. were exposed to test chemical in 25 ml beakers in a volume of 20 ml of liquid solution containing both the chemical and media. The beakers were placed in a room at a temperature of 20±2°C, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions with light intensity 1000 – 1500 Lux, respectively. One control vessel was also run simultaneously during the study. The animals in control and test chemical concentrations were exposed for a period of 48 hour. No Immobility were found in the control test animals and the dissolved oxygen concentration at the end of the test in the control and test vessel was ≥ 3 mg/l. On the basis of effect of test chemical on mobility of the test organism, the median effect concentration (EC50 (48 h)) value was determined to be >100 mg/L. Thus, based on the EC50 value, chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

A freshwater algal growth inhibition test was conducted for 72 hrs for assessing the effect of test chemical on green algae. The test was performed in accordance to OECD guideline No. 201 – Alga growth inhibition test under static condition.Chlorella vulgaris(green algae)was used as a test organism for the study. Initial cell density of the culture was kept at 1 х 10000 cells/ml. Bold’s Basal Medium (BBM) composed of macronutrients, micronutrients, alkaline EDTA solution and iron solution was used as a growth medium for the study. The test chemical was prepared by dissolving 50 mg of test substance in 250 ml of BBM to get the final concentration of 200 mg/l. The remaining test solutions were prepared by dilution from the above stock solution. All the final test solutions were prepared under aseptic condition. 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. Nominal test chemical concentration used for the study were 0, 6.25 mg/L,12.5 mg/L, 25 mg/L, 50 mg/L, 100 mg/L and 200 mg/L. All the six concentration were in geometric series spaced by a factor of 2.Green algae were exposed to various nominal concentration of test chemical in 100 ml conical flasks. Test vessel were placed in orbital shaking incubator for 72 hrs at a room at a temperature of 22±2°C under a photoperiod of 16:8 hr light: dark conditions and with a continuous uniform illumination of 1500 lux light intensity, respectively. The speed of the orbital shaking incubator was set at a 120 revolutions per minute throughout the study period. Control (containing only the test medium) was also included in the test.The cultures were observed daily with the helpof an automated cell counter to verify a normal and healthy appearance of the algae cells 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 an automated cell counter.As per the OECD guideline No. 201 – Alga growth inhibition test, the biomass in the control cultures have increase exponentially by a factor of at least 16 within the 72 hr test period which corresponds to a specific growth rate of 0.92 per day, the mean coefficient of variation by section specific growth rate in the control cultures not exceeded 35% (i.e., reported as 24.22%) and the coefficient of variation of average specific growth rate during the whole test period in replicate control cultures was not exceeded 10% (i.e., reported as 5.09%), thus, fulfilling the validity of the criteria. In the control vessel, all cells appeared healthy,round and green throughout the study duration. The microscopic observations were also noted in each of the test vessel. All the cells appeared healthy, round and green throughout the study duration and no significant changes were observed up to the concentration of 200 mg/l. On the basis of growth rate of the test organismChlorella vulgaris, the 72 hrs EC50 value was determined to be >200 mg/l.Thus, based on the EC50 value, chemical can be considered as non-toxic to aquatic algae and can be considered to be not classified as per CLP classification criteria.

 

Toxicity to microorganisms

Toxicity to marine bacteria Vibrio fischeri study was carried out for 30 mins (Sónia P. M. Ventura et. al., 2016). The standard Microtox toxicity test liquid-phase assay was used to evaluate the inhibition of the marine bacteria Vibrio fischeri bioluminescence at 15 °C and pH 7.0. The test was performed by measuring the bacteria luminescence variation when exposed to test chemical concentrations, with successive dilutions by a factor of 2 (from 0.32 to 81.9%), in which 100% of the compound corresponds to a known concentration (this concentration varies with the compound tested) of a stock solution, in which 0% corresponds to the control. After 5, 15, and 30 minutes of exposure to the compound, the light output of the luminescent bacteria was measured and compared with the light output of a blank control. The toxicity was evaluated, a 50% reduction in luminescence, corresponding to the EC50, and the respective 95% confidence intervals were computed using the Microtox Omni™ Software version 4.3.0.1. Additional statistical analysis, namely the respective 95% confidence intervals, which were estimated for each compound by non-linear regression, using the least squares method to fit the data to the logistic equation, was performed by the STATISTICA software, version 8.0. On the basis of the inhibition bioluminescence response of the marine bacteria Vibrio fischeri, median effective concentration (EC50) value after 5, 15 and 30 min was determined to be 15.6 mg/l (95% C. I. = 14.8 to 16.5 mg/l), 15.4 mg/l (95% C. I. = 14.3 to 16.4 mg/l) and 14.9 mg/l (95% C. I. = 14.2 to 15.6 mg/l), respectively.

Additional information

Short term toxicity to fish

Experimental study of the test chemical and various supporting weight of evidence studies for its read across chemical were reviewed for short term toxicity to fish end point which are summarized as below:

 

In an experimental study from study report, short term toxicity to fish was conducted for 96 hrs for assessing the effect of test chemical. The test was performed in accordance to OECD guideline No. 203 “Fish Acute Toxicity Test”. Zebra fish (Danio rerio) of average weight 0.045 g and average length of 1.4 cm was used as a test organism for the study. Test fishes were kept in a static tank in tap water passed through reverse osmosis system, under natural conditions along with proper feed and aeration. During the housing period, test fishes were fed once daily with standard brand fed. The test conditions during the housing of the test organisms were oxygen content of 7.6 mg/l, pH 7.5, water temperature 23.9°C and under a photoperiod of 16:8 hr light: dark conditions, respectively. Test was performed using test chemical concentrations of 0, 3.125 mg/l, 6.25 mg/l, 12.5 mg/l, 25 mg/l and 50 mg/l, respectively. Total 8 fishes were exposed to test chemical in a 5 lit bowl aquaria containing 4 liters of potable water. The test vessels were placed in a room at a temperature of 23.9°C, pH 7.2, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions, respectively. Aeration in test vessels was provided 1 day before the start of the experiment. No mortalities were observed in the control. Test fishes were moving slowly as compared to control. On the basis of effect of test chemical on mortality of the test organism, the median lethal concentration (LC50 (96 h)) was determined to be 50 mg/l. Thus, based on the LC50 value, test chemical was considered as toxic to aquatic fishes. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be not classified as per the CLP classification criteria.

 

In a supporting weight of evidence study, short term toxicity to fish study (from authoritative database, 2018 and secondary source, 1976) was carried out for 96 hrs. Pimephales promelas (Fathead minnow) (Juvenile) of length of 1.1 to 3.1 cm and 4 to 8 weeks old obtained from the Environmental Research Laboratory was used as a test organism. Fish were acclimated in flowing water 11 cm deep in a holding trough (360 cm long by 58 cm wide by 31 cm deep) for at least 48 hr before the tests. Fishes were acclimated in lake superior water. Test organisms were fed Glencoe trout chow no. 3 granules. Three to five widely spaced test concentrations differing by a factor of 10 or more and a control were used. Test solutions were prepared by adding a weighed amount of chemical' to a 9-1. glass carboy containing 4 lit of Lake superior water. Solution components were thoroughly mixed by shaking and were then poured into two glass battery jars for preparation of the toxicant test concentrations. All chemical concentrations are nominal; none were analyzed to determine concentration levels. Test were tested in both lake superior and reconstituted water. The reconstituted water was prepared by adding NaHC03, CaS04. 2H20, MgS04, and KCl salts to distilled water. The static tests were conducted in 3 lit cylindrical glass battery jars containing 2 lit of test water. A glass cover was placed over each jar to reduce evaporation. Test water was not aerated. Test fishes were not fed during the study.  Test fishes (20 fish/conc.) were exposed to test chemical for 96 hr at a temperature of 18 to 22°C. Complete immobilization of the fish was considered as the biological endpoint and equated with death. Fish mortality was measured after 1, 24, 48, and 96 hr. Standard graphical procedures were followed for determining concentrations that would result in 50% mortality. On the basis of the effect of test chemical on mortality of the test organism Pimephales promelas (Fathead minnow), the 96 hr LC50 value was determined to be 32 mg/l. Thus, based on the LC50 value, test chemical was considered as toxic to aquatic fishes. Since the test chemical is readily biodegradable in water, chemical was considered as non-toxic to fishes at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

 

For the test chemical from authoritative database (2020), acute toxicity to fish study was carried out. Study was performed following the principles of OECD Guideline 203 (Fish, Acute Toxicity Test). Study was performed under static conditions for a period of 96 hrs. On the basis of the effect of test chemical on mortality of the test organism, the 96 hr LC50 value was determined to be >120 mg/l. Thus, based on the EC50 value, test chemical was considered as non-toxic to aquatic fishes at environmental relevant concentrations and hence, considered to be 'not classified' as per the CLP classification criteria.

 

On the basis of the above results, it can be concluded that the test chemical was considered to be toxic to aquatic fishes. Since the test chemical is readily biodegradable in water, test chemical was considered as non-toxic to aquatic fishes and hence, considered to be not classified as per the CLP classification criteria.

Short term toxicity to aquatic invertebrates

Experimental study of the test chemical and various supporting weight of evidence studies for its read across chemical were reviewed for short term toxicity to aquatic invertebrate end point which are summarized as below:

 

In an experimental study from study report, an acute immobilisation test was conducted for 48 hrs for assessing the effect of test chemical on Daphnia magna. The test was performed in accordance to OECD guideline No. 202“Daphnia sp.,Acute Immobilization Test”. The test solution was prepared by dissolving 100mg of test chemical in 100ml of ADaM’s media. Achieving test concentrations of 1 g/L, respectively. Test chemical concentrations used for the study were 0, 6.25 mg/l, 12.5 mg/l, 25 mg/l, 50 mg/l and 100 mg/l, respectively. Study was performed using 10 daphnids in a static system. Total 10 Daphnids/conc. were exposed to test chemical in 25 ml beakers in a volume of 20 ml of liquid solution containing both the chemical and media. The beakers were placed in a room at a temperature of 20±2°C, hardness of water 155.5 mg of CaCO3 and under a photoperiod of 16:8 hr light: dark conditions with light intensity 1000 – 1500 Lux, respectively. One control vessel was also run simultaneously during the study. The animals in control and test chemical concentrations were exposed for a period of 48 hour. No Immobility were found in the control test animals and the dissolved oxygen concentration at the end of the test in the control and test vessel was ≥ 3 mg/l. On the basis of effect of test chemical on mobility of the test organism, the median effect concentration (EC50 (48 h)) value was determined to be >100 mg/L. Thus, based on the EC50 value, chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be 'not classified' as per CLP classification criteria.

 

In a supporting weight of evidence study, short term toxicity to aquatic invertebrate study was conducted for 48 hrs for assessing the effect of test chemical (authoritative database, 2018). The study was performed under static conditions using Daphnia magna (Water flea) as a test organism. On the basis of the effect of test chemical on mobility of the test organism Daphnia magna, the 48 hr median effect concentration (EC50) value was determined to be 27 mg/l. Thus, test chemical was considered as toxic to aquatic invertebrates at environmental relevant concentrations. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic and hence, considered to ‘not classified’ as per the CLP classification criteria.

 

Another short term toxicity to aquatic invertebrate study was conducted for 48 hrs for assessing the effect of test chemical. The study was performed following the principles of the OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test) under static conditions using Daphnia magna (Water flea) as a test organism. On the basis of the effect of chemical on mobility of the test organism Daphnia magna, the 48 median effect concentration (EC50) value was determined to be 110 mg/l. Thus, test chemical was considered as non-toxic to aquatic invertebrates at environmental relevant concentrations and hence, considered to be ‘not classified’ as per the CLP classification criteria.

 

On the basis of the above results, it can be concluded that the test chemical was considered to be toxic to aquatic invertebrates. Since, the test chemical is readily biodegradable in water, chemical was considered as non-toxic to aquatic invertebrates and hence, considered to be not classified as per the CLP classification criteria.

Toxicity to aquatic algae and cyanobacteria

Experimental study of the test chemical and supporting weight of evidence study for its read across chemical were reviewed for toxicity to aquatic algae and cyanobacteria end point which are summarized as below:

 

In an experimental study from study report, a freshwater algal growth inhibition test was conducted for 72 hrs for assessing the effect of test chemical on green algae. The test was performed in accordance to OECD guideline No. 201 – Alga growth inhibition test under static condition. Chlorella vulgaris (green algae) was used as a test organism for the study. Initial cell density of the culture was kept at 1 х 10000 cells/ml. Bold’s Basal Medium (BBM) composed of macronutrients, micronutrients, alkaline EDTA solution and iron solution was used as a growth medium for the study. The test chemical was prepared by dissolving 50 mg of test substance in 250 ml of BBM to get the final concentration of 200 mg/l. The remaining test solutions were prepared by dilution from the above stock solution. All the final test solutions were prepared under aseptic condition. 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. Nominal test chemical concentration used for the study were 0, 6.25 mg/L,12.5 mg/L, 25 mg/L, 50 mg/L, 100 mg/L and 200 mg/L. All the six concentration were in geometric series spaced by a factor of 2.Green algae were exposed to various nominal concentration of test chemical in 100 ml conical flasks. Test vessel were placed in orbital shaking incubator for 72 hrs at a room at a temperature of 22±2°C under a photoperiod of 16:8 hr light: dark conditions and with a continuous uniform illumination of 1500 lux light intensity, respectively. The speed of the orbital shaking incubator was set at a 120 revolutions per minute throughout the study period. Control (containing only the test medium) was also included in the test. The cultures were observed daily with the help of an automated cell counter to verify a normal and healthy appearance of the algae cells 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 an automated cell counter. As per the OECD guideline No. 201 – Alga growth inhibition test, the biomass in the control cultures have increase exponentially by a factor of at least 16 within the 72 hr test period which corresponds to a specific growth rate of 0.92 per day, the mean coefficient of variation by section specific growth rate in the control cultures not exceeded 35% (i.e., reported as 24.22%) and the coefficient of variation of average specific growth rate during the whole test period in replicate control cultures was not exceeded 10% (i.e., reported as 5.09%), thus, fulfilling the validity of the criteria. In the control vessel, all cells appeared healthy, round and green throughout the study duration. The microscopic observations were also noted in each of the test vessel. All the cells appeared healthy, round and green throughout the study duration and no significant changes were observed up to the concentration of 200 mg/l. On the basis of growth rate of the test organism Chlorella vulgaris, the 72 hrs EC50 value was determined to be >200 mg/l. Thus, based on the EC50 value, chemical can be considered as non-toxic to aquatic algae and can be considered to be not classified as per CLP classification criteria.

 

For the test chemical from authoritative database (2019), Toxicity to aquatic algae study was carried out for assessing the effect of test chemical. The study was performed following the principles of OECD Guideline 201 (Alga, Growth Inhibition Test) under static conditions. Based on the effect of test chemical on growth rate of the test algae, the 72 hr NOEC and EC50 value was determined to be 4.4 and > 58 mg/l, respectively.

 

On the basis of the above results, it can be concluded that the test chemical was considered to be non-toxic to aquatic algae and hence, considered to be 'not classified' as per the CLP classification criteria.

Toxicity to microorganisms

Experimental study of the test chemical and various supporting weight of evidence studies for its read across chemical were reviewed for toxicity to micro-organisms end point which are summarized as below:

 

In an experimental study from peer reviewed journal (Sónia P. M. Ventura et. al., 2016), toxicity toxicity to marine bacteria Vibrio fischeri study was carried out for 30 mins. The standard Microtox toxicity test liquid-phase assay was used to evaluate the inhibition of the marine bacteria Vibrio fischeri bioluminescence at 15 °C and pH 7.0. The test was performed by measuring the bacteria luminescence variation when exposed to test chemical concentrations, with successive dilutions by a factor of 2 (from 0.32 to 81.9%), in which 100% of the compound corresponds to a known concentration (this concentration varies with the compound tested) of a stock solution, in which 0% corresponds to the control. After 5, 15, and 30 minutes of exposure to the compound, the light output of the luminescent bacteria was measured and compared with the light output of a blank control. The toxicity was evaluated, a 50% reduction in luminescence, corresponding to the EC50, and the respective 95% confidence intervals were computed using the Microtox Omni™ Software version 4.3.0.1. Additional statistical analysis, namely the respective 95% confidence intervals, which were estimated for each compound by non-linear regression, using the least squares method to fit the data to the logistic equation, was performed by the STATISTICA software, version 8.0. On the basis of the inhibition bioluminescence response of the marine bacteria Vibrio fischeri, median effective concentration (EC50) value after 5, 15 and 30 min was determined to be 15.6 mg/l (95% C. I. = 14.8 to 16.5 mg/l), 15.4 mg/l (95% C. I. = 14.3 to 16.4 mg/l) and 14.9 mg/l (95% C. I. = 14.2 to 15.6 mg/l), respectively.

 

In a supporting weight of evidence study, toxicity to Pseudomonas putida study (from peer reviewed journal (1980), handbook and secondary source) was carried out for 16 hr. The study was based on the effects of the test chemical on Pseudomonas putida at a temperature of 25°C. Test chemical of known concentration was prepared in sterile double distilled water. Composition of test medium contains sodium nitrate (1.06 g), dipotassium hydrogen phosphate (0.6 g), magnesium sulphate (0.2 g), D (+) glucose (10 g), Difco bacto agar (18 g), ferrous sulphate (0.001 g), and 1.5 ml trace element solution. Pseudomonas putida was used as a test organism. Keep stock cultures of the test strain, Pseudomonas putida, on the nutrient for stock and preliminary cultures in agar slant tubes. Prepare, for onward culturing of the test strain, new stock cultures at intervals of 1 week each. Incubate the inoculated stock cultures at 25"C for 24 h and keep in stock. stock. If needed, prepare preliminary cultures from stock cultures on the above mentioned nutrient medium in agar slant tubes and incubate at 25°C for 24 h. Then, wash off the cell material with sterile saline. Determine the extinction of the monochromatic radiation at 436nm for a 10 mm layer of the bacterial suspension by photoelectric measurement. Erlenmeyer flask of 300 ml stoppered with cottoned lined plastic caps was used for the study. Prepare dilution series in the test vessel. Each of the dilutions contains 1 part v/v of the pollutant solution in 20 to 214 parts v/v of mixture. Prepare the dilution series as follows: the first flask of each series contains 160ml of pollutant solution at the start. Starting from this flask prepare the subsequent dilution stein at a constant dilution ratio by consistently mixing 80ml of preliminary pollutant dilution and 80 ml double distilled water. Consequently, each flask contains 80 ml of culture liquid at the start. Make up each flask of the three dilution series to beinoculatedto 100 ml by adding 5 ml each of stock solution I, 5 ml each of stock solution II and I0 ml each of the prepared bacterial suspension from the preliminary culture having a known adjusted extinction value. Leave both inoculated and non-inoculated dilution series at 25°C for 16 h. After termination of the test period measure the extinction of the monochromatic radiation at 436 nm in a 10-mm layer in the inoculated dilution series. On the basis of the effect of test chemical on growth rate, i.e., multiplication of the test organism Pseudomonas putida, the 16 h EC0 and EC50 value was determined to be 16 and > 16 mg/l.

 

For the test chemical from peer reviewed journal, toxicity to marine bacteria Vibrio fischeri study was carried out for 30 mins. The standard Microtox toxicity test liquid-phase assay was used to evaluate the inhibition of the marine bacteria Vibrio fischeri bioluminescence at 15 °C and pH 7.0. The test was performed by measuring the bacteria luminescence variation when exposed to test chemical concentrations, with successive dilutions by a factor of 2 (from 0.32 to 81.9%), in which 100% of the compound corresponds to a known concentration (this concentration varies with the compound tested) of a stock solution, in which 0% corresponds to the control. After 5, 15, and 30 minutes of exposure to the compound, the light output of the luminescent bacteria was measured and compared with the light output of a blank control. The toxicity was evaluated, a 50% reduction in luminescence, corresponding to the EC50, and the respective 95% confidence intervals were computed using the Microtox Omni™ Software version 4.3.0.1. Additional statistical analysis, namely the respective 95% confidence intervals, which were estimated for each compound by non-linear regression, using the least squares method to fit the data to the logistic equation, was performed by the STATISTICA software, version 8.0. On the basis of the inhibition bioluminescence response of the marine bacteria Vibrio fischeri, median effective concentration (EC50) value after 5, 15 and 30 min was determined to be 10.4 mg/l (95% C. I. = 9.3 to 11.5 mg/l), 9.66 mg/l (95% C. I. = 8.53 to 10.8 mg/l) and 9.57 mg/l (95% C. I. = 8.31 to 10.8 mg/l), respectively.

 

On the basis of the experimental studies, the EC50 value of the test chemical on test organism was determined to be ranges from 9.57 to > 16mg/l, respectively.

On the basis of the available information of aquatic toxicity studies and readily biodegradable in water of test chemical, it can be concluded that the test chemical was considered to be non-toxic to aquatic organisms at environmental relevant concentrationsand hence, considered to be 'not classified' as per the CLP classification criteria.