Imazosulfuron

412.81

412.81

602-788-7

27LUJ2BJDG

DTXSID2057946

White, crystalline powder

29350090

145

2.51

d25 1.574

183 °C (decomp)

1.716

1.63e-05 M

0-6°C

3.38e-10 mmHg

pH = 4.61 at 25 °C (1% suspension in water)

pKa = 3.94 in methanol/0.01 M citrate buffer at 252 nm

log Kow = 1.88 (pH 4), 1.59 (pH 7), <0.29 (pH 9). pKa: 2.2, 3.82, 9.25. Vapor pressure: <4.73X10-6 mm Hg at 25 °C|Henry's Law constant = 3.7X10-11 atm-cu m/mole at 25 °C (estimated from vapor pressure and water solubility (pH 5.1, 25 °C); calculated value at higher pH will be even lower due to higher water solubility|Hydroxyl radical reaction rate constant = 2.1X10-10 cu-cm/molc sec at 25 °C (est)

NONH for all modes of transport

1

Stable under recommended storage conditions.

P273, P391, P501

H400

SRP: Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.|Product: Offer surplus and non-recyclable solutions to a licensed disposal company; Contaminated packaging: Dispose of as unused product.

Incompatible materials: Strong oxidizing agents.

USEPA/Office of Prevention, Pesticides and Toxic Substances; Interim Reregistration Eligibility Decision (IRED) for 22 Sulfonylurea (SU) Herbicides EPA-HQ-OPP-2015-0625-0044 (June 2017). EPA issues an IRED for a pesticide that is undergoing reregistration, requires a reregistration eligibility decision, and also needs a cumulative assessment under FQPA. The IRED, issued after EPA completes the individual pesticide's aggregate risk assessment, may include taking risk reduction measures -- for example, reducing risks to workers or eliminating uses that the registrant no longer wishes to maintain -- to gain the benefits of these changes before the final RED can be issued following the Agency's consideration of cumulative risks.[Available from, as of July 31, 2018: https://iaspub.epa.gov/apex/pesticides/f?p=chemicalsearch:1]

|Warning|H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]|P273, P391, and P501|Aggregated GHS information provided by 157 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|The GHS information provided by 1 company from 1 notification to the ECHA C&L Inventory.|Danger|H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]|P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P405, and P501

Eye/face protection: Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).|Skin protection: Handle with gloves.|Body Protection: Choose body protection in relation to its type, to the concentration and amount of dangerous substances, and to the specific work-place.|Respiratory protection: Respiratory protection is not required. Where protection from nuisance levels of dusts are desired, use type N95 (US) or type P1 (EN 143) dust masks. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Suitable extinguishing media: Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.|Advice for firefighters: Wear self contained breathing apparatus for fire fighting if necessary.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid dust formation. Avoid breathing vapors, mist or gas. Environmental precautions: Do not let product enter drains. Methods and materials for containment and cleaning up: Sweep up and shovel. Keep in suitable, closed containers for disposal.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Avoid dust formation. Avoid breathing vapors, mist or gas. Environmental precautions: Do not let product enter drains.|Precautions for safe handling: Provide appropriate exhaust ventilation at places where dust is formed. Normal measures for preventive fire protection.|Appropriate engineering controls: General industrial hygiene practice.|Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.|SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants. Ensure that the local ventilation moves the contaminant away from the worker.

IDENTIFICATION AND USE: Imazosulfuron is a herbicide, which is used to control most annual and perennial broad-leaved weeds and sedges in paddy rice and turf. HUMAN STUDIES: In a case report, ingestion of imazosulfuron and mefenacet changed urine color to green almost immediately. ANIMAL STUDIES: In mice, treatment-related increase in the mean relative liver weight was observed in males at 10,000 and 45,000 ppm and in females at 45,000 ppm. In rats treated for 24 months, examination of the eyes revealed treatment-related retinal degeneration and posterior subcapsular or complete cataracts at 20,000 ppm in males at termination (24 months) and in females at 6 months (cataracts only), 12 months, and 18 months. Microscopic examination revealed bilateral retinal atrophy in both sexes at 20,000 ppm and bilateral lens cataracts in females at 20,000 ppm. Histopathological examination revealed no treatment-related neoplasms. A treatment-related decrease in mean live litter size in both F0 and F1 generations was observed at 10,000 ppm in rats. No treatment-related fetal malformations or developmental variations were observed. An increase in chromatid breaks and chromatid exchanges were observed at 500 ug/mL in cells cultured without metabolic activation in cultures of Chinese hamster lung fibroblasts.

Imazosulfuron's production may result in its release to the environment through various waste streams; its use as a selective herbicide providing both pre- and post-emergence control of sedges and broadleaf weeds(1) will result in its direct release to the environment(SRC). Imazosulfuron is registered for application to residential and commercial turfgrass, rice, tomatoes, and peppers(1).

TERRESTRIAL FATE: Based on a classification scheme(1), a measured Koc range of 98.7-208(2), indicates that imazosulfuron is expected to have high to moderate mobility in soil(SRC). A pKa of 3.94(3) indicates imazosulfuron will exist partially in anion form at pH 5 and almost entirely in anion form at pH 6-9(SRC). Studies in pH-modified soils indicated sorption was stronger at low pHs where neutral imazosulfuron existed compared to soils of pH 7.4-7.5 where anionic imazosulfuron dominated(2). Volatilization of neutral imazosulfuron from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.7X10-11 atm-cu m/mole(SRC), derived from its vapor pressure, 3.38X10-10 mm Hg(4), and water solubility, 5 mg/L at pH 5(5). Imazosulfuron in anion form will not volatilize. Imazosulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(SRC). In one report, imazosulfuron was classified as not readily biodegradable based on <10% degradation over a 30-day period(6). Imazosulfuron biodegraded readily under anaerobic conditions in flooded soil, but not under aerobic conditions(7). Dissipation of imazosulfuron in the soil environment results from biodegradation, photolysis(3) and abiotic hydrolysis in acidic soils(7). Soil dissipation half-lives under laboratory conditions were 21-75 days under aerobic conditions and 11-13 days under anaerobic conditions(6). Field dissipation half-lives are reported as 21-91 days(6). A geometric mean dissipation half-life of 71.1 days has been reported(6).|FIELD STUDY: Imazosulfuron is a new post-emergence sulfonylurea herbicide. It is highly active at low application rates to control annual and perennial broad-leaf weeds and sedges in rice. There is increasing concerned about the persistence of pesticide residues in soils, crop produce and subsequent contamination of groundwater. Thus persistence of imazosulfuron residues under field condition was evaluated. Imazosulfuron was applied at 30, 40, 50 and 60 a. i. g ha (-1) rates, 4 days after transplanting of rice as post-emergence herbicide. Soil and plant samples treated with imazosulfuron were collected at 60, 90 and 120 days after herbicide application and analyzed for residues. Rice grains and straw samples were sampled at harvest (120 days). Residues of imazosulfuron in soil were not found after 90 and 120 DAS (days after spraying). Rice grains contained 0.006, 0.009 microg g(-1) residues at 50 and 60 g ha (-1) application rates. 0.009 and 0.039 microg g(-1) residues of imazosulfuron were detected at 50 and 60 g/ha rates respectively in rice straw. Residues of imazosulfuron were not detected applied at 30 and 40 g ha(-1) in rice grains and straw, respectively and can be safely applied to the transplanted rice.|AQUATIC FATE: Based on a classification scheme(1), a measured Koc range of 98.7-208(2), indicates that imazosulfuron is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 3.94(3) indicates this compound will exist partially in anion form at pH 5 and almost entirely in the anion form at pH 6-9 in the environment(SRC), and volatilization of the anion form from water surfaces is not expected to be an important fate process(SRC). Volatilization from water surfaces is also not expected from the neutral form(4) based upon an estimated Henry's Law constant of 3.7X10-11 atm-cu m/mole(SRC), derived from its vapor pressure, 3.38.5X10-10 mm Hg(5), and water solubility, 5 mg/L at pH 5(6). According to a classification scheme(7), an estimated BCF of 19(SRC), from its log Kow of 2.43(3) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is low(SRC). In one report, imazosulfuron was classified as not readily biodegradable based on <10% degradation over a 30-day period(9). Imazosulfuron biodegraded readily under anaerobic conditions in flooded soil, but not under aerobic conditions(10). Dissipation of imazosulfuron in the aquatic environment results from biodegradation, photolysis(3) and abiotic hydrolysis in acidic waters(10). An aquatic photolysis half-life of 3.5 days has been reported(3). The hydrolysis half-life at pH 4.5-5.0 (25 °C) is 27-36.5 days(11,12); imazosulfuron is stable to hydrolysis at pH 6.6 and higher(11,12). The dissipation half-life of imazosulfuron in water-sediment systems ranged from 21-479 days(11).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), imazosulfuron, which has a vapor pressure of 3.38X10-10 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase imazosulfuron may be removed from the air by wet and dry deposition(SRC). Imazosulfuron has a quantum yield of 0.00262 in water at wavelengths >290 nm(3) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC).

The half-life for the hydrolysis of imazosulfuron in aqueous buffer at 25 °C was determined as follows (in days): 3.30 (pH 1.9), 4.33 (pH 2.8), 6.30 (pH 3.6), 36.5 (pH 4.5), 578 (pH 5.9) and at pH 6.6-12.3, no hydrolysis occurred over 150 days(1). Hydrolysis measurement over a range of temperatures found a 3-5 fold increase in the hydrolysis rate for each 10 °C increase in temperature(1). The hydrolysis products were the result of cleavage of the sulfonylurea bridge(1). Hydrolytic half-lives at 25 °C have also been reported as: 27 days (pH 5) and stable at pH 7 and pH 9(2). Imazosulfuron has a quantum yield of 0.00262 in water at wavelengths >290 nm(2) and, therefore, is expected to be susceptible to direct photolysis by sunlight(SRC). An 8 hour irradiation of aqueous solutions at pH 7.6 and pH 9 by a xenon lamp resulted in photostability half-lives of <3 to <4 hours(2). An aquatic photolysis half-life of 3.5 days has been reported (study details not reported)(3).|... The photodegradation of imazosulfuron (IMZ), a potent broad-spectrum herbicide, was investigated under simulated rice field conditions. Previous reports have indicated that it is photolabile, but have failed to report radiation intensity or determine a quantum yield, precluding extrapolation to environmental rates. Therefore, the objective of this investigation was to determine the photolytic rate of IMZ under simulated rice field conditions and how it is influenced by environmental factors such as turbidity, salinity and temperature. RESULTS: IMZ was efficiently photolyzed in all solutions and fitted pseudo-first-order kinetics. Degradation was faster in HPLC-grade water than in field water. Field-relevant variances in temperature, turbidity and salinity did not significantly influence degradation. The experimentally derived quantum yield for direct photolysis (2.9X10+3) was used to predict the half-life of IMZ in a California rice field (3.6 days). CONCLUSIONS: Aqueous photolysis is predicted to be an important process in the overall degradation of IMZ in the environment, regardless of variances in salinity, organic matter and temperature. Based on the predicted half-life of IMZ in a California rice field (3.6 days), state-mandated holding periods for field water post-IMZ application (30 days) are expected to allow for sufficient clearance of the herbicide (>98%), preventing significant contamination of the environment upon release of tailwater.

An estimated BCF of 19 was calculated in fish for imazosulfuron(SRC), using a log Kow of 2.43(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC). Bioacccumulation in fish is reported to be "not relevant" as an ecotoxicological factor in aquatic organisms(4).

Soil sorption studies using four Italian soils determined imazosulfuron Koc values of 98.7, 102 and 117 in soils of pH 7.0-7.5 and a Koc of 208 in a soil of pH 4.5(1). Additional tests in pH-modified soils indicated that imazosulfuron adsorption generally increased as the pH of the soil decreased(1); with a pKa of about 4, imazosulfuron at pH 7 and above will exist almost entirely in anionic form that can be repelled by negatively charged clay particles in soils lowering overall sorption(1); soil Kd values measured in one pH-modified sandy clay soil were 102 (pH 2.5), 6.58 (pH 4.4) and 0.91-1.76 (pH 7.4-7.5)(1). A measured Koc range 111-215 has also been reported(2,3) with a mean Koc of 163(2). According to a classification scheme(4), these Koc values suggests that imazosulfuron is expected to have high to moderate mobility in soil(SRC). Lysimeter studies conducted under field conditions with a soil having a pH of 5.6-5.85 found that C14-labeled-imazosulfuron and its degradation products were only slightly translocated into groundwater(5). Because imazosulfuron is mobile to moderately mobile in soil, it is expected to move from the herbicide application site into groundwater and surface water(6).

A pKa of 3.94(1) indicates imazosulfuron will exist partially in anion form at pH 5 and almost entirely in anion form at pH 6-9(SRC), and therefore, since anions do not volatilize, volatilization of anionic imazosulfuron will not be an important fate process(SRC). The Henry's Law constant for non-ionized imazosulfuron is estimated as 3.70X10-11 atm-cu m/mole(SRC) derived from its vapor pressure, 3.38X10-10 mm Hg(2), and water solubility, 5 mg/L at pH 5(3). This Henry's Law constant indicates that non-ionized imazosulfuron is expected to be essentially nonvolatile from water surfaces(4). Imazosulfuron's estimated Henry's Law constant and ionization indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Imazosulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. Imazosulfuron is not volatile and, therefore, is not likely to be transported via atmospheric processes following herbicidal applications(1).

GROUNDWATER: The mobility and degradation of imazosulfuron, labeled with carbon-14 at the imidazole ([imi-(14)C]imazo) or pyrimidine ring ([pyr-(14)C]imazo), in lysimeters with 1 m(2) surface and 110 cm depth were investigated for three years. One lysimeter was treated with [imi-(14)C]imazo in two successive years at the rate of 50 g of active ingredient (ai)/ha each. The other two lysimeters were treated once with [pyr-(14)C]imazo and a mixture (1:1, w/w) of the two labeled imazosulfurons, respectively (50 g of ai/ha). In the first and second years of monitoring, the yearly mean concentration of (14)C in the leachate water was <0.10 microg/L in each lysimeter. Although in the third year the concentration of (14)C in the leachate water was 0.17 microg/L for the lysimeter treated twice with [imi-(14)C]imazo, the concentration of imazosulfuron and its degradation products in the leachate water ranged from 0.01 to 0.06 microg/L. At the study termination, the main portion of (14)C recovered was found in the upper 30 cm soil layer in each lysimeter, and no (14)C was detected below a depth of 50 cm. These findings indicated that imazosulfuron and its degradation products in soils translocated into groundwater only slightly.

Occupational exposure to imazosulfuron may occur through inhalation and dermal contact with this compound at workplaces where imazosulfuron is produced or used. The general population may be exposed to imazosulfuron via inhalation and dermal contact in localized areas where imazosulfuron is being applied or recently applied as a herbicide(SRC). There is a potential for exposure of homeowners applying products containing imazosulfuron on home lawns(1). There is also a potential for post-application exposure of adults and children entering turf areas that have been treated with imazosulfuron and for bystander exposure of adults and children in areas adjacent to pesticide applications(1).

Two test articles were used in this study: 1. [im-(14)C]imazosulfuon, specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0% together with unlabeled imazosulfuron, purity = 98.6% and 2. [pm-(14)C]imazosulfuon, specific activity 2.04 Gbq/mmol, radiochemical purity> 98.6% together with unlabeled imazosulfuron, purity = 98.6%, each of which was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 1 Crl:CD (SD) rat per sex. (14)C excretion into the expired air was negligible. Fecal and urine samples were collected at 1, 2, and 3 days after the administration of the dosing compounds. For [im-(14)C]imazosulfuon, 65.3% (male) and 69.0% (female) of radio-labeled dose was eliminated in the urine and 36.8% (male) and 31.8% (female) of the radio-labeled dose was eliminated in the feces 72 hours after dosing. For [pm- (14)C]imazosulfuon, 64.4% (male) and 57.9% (female) of radio-labeled dose was eliminated in the urine and 37.2% (male) and 40.1% (female) of the radio-labeled dose was eliminated in the feces 72 hours after dosing. Both [im-(14)C]imazosulfuon and [pm-(14)C]imazosulfuon were extensively metabolized. For [im-(14)C]imazosulfuon, metabolites HMS (54.6% of the dose in the male and 58.2% of the dose in the female) and IHDU (2.7% of the dose in the male and 4.3% of the dose in the female) were excreted in the urine 24 hours after dosing and metabolites HMS (6.9% of the dose in the male and 5.6% of the dose in the female), IHDU (0.8% of the dose in male and 0.3% of the dose in female), and ACIS (6.0% of the dose in the male and 4.3% of the dose in the female) were excreted in the feces 48 hours after dosing. For [pm-(14)C]imazosulfuon, metabolites HMS (50.3% of the dose in the male and 47.8% of the dose in the female) and IHDU (5.1% of the dose in the male and 3.1% of the dose in the female) were excreted in the urine 24 hours after dosing and metabolites HMS (5.3% of the dose in the male and 13.4% of the dose in the female), IHDU (0.7% of the dose in the male and 0.5% of the dose in the female), and UK-1 (3.8% of the dose in the male and 4.0% of the dose in the female) were excreted in the feces 48 hours after dosing. From the identified metabolites, metabolic reactions were determined to be demethylation, hydroxylation of the pyrimidine ring, opening of the pyrimidine ring, and hydrolysis of the sulfonylurea bridge.|[im-(14)C]Imazosulfuron (specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0%) together with unlabeled imazosulfuron (purity = 98.6%) was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 4 male Crl:CD (SD) rats. Fecal and urine samples were collected at 6 and 12 hours (urine only), and 24, 48, and 72 hours after the administration. 64.1% of radio-labeled dose was eliminated in the urine and 32.4% of the radio-labeled dose was eliminated in the feces 72 hours after dosing. The highest mean tissue concentrations of the radio-labeled dose were found in the carcass (0.15%), blood (0.04%), and liver (0.04%). [Imidazopyridinyl-3-(14)C] Imazosulfuron was extensively metabolized. Metabolites HMS (55.7% of the dose), IHDU (4.1% of the dose), and HDS (1.9% of the dose) were excreted in the urine 48 hours after dosing. Metabolites HMS (6.5% of the dose), IHDU (0.4% of the dose), HDS (2.3% of the dose), IPSN (2.9% of the dose, from extracts 1 and 3), and ACIS (3.2% of the dose from extracts 1 and 3) were excreted in the feces 48 hours after dosing. From the identified metabolites, metabolic reactions were determined to be demethylation, hydroxylation, methylation of the hydroxyl group, opening of the pyrimidine ring, and hydrolysis of the sulfonylurea bridge.|[im-(14)C]Imazosulfuron (specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0%) together with unlabeled imazosulfuron (purity = 98.6%) was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 3 bile duct-cannulated male Crl:CD (SD) rats. Feces, bile, and urine samples were collected at 6 and 12 hours (urine and bile only), and 24, 48, and 72 days after the administration of the dosing material. 53.4% and 30.5% of the radio-labeled dose was eliminated in the urine and bile, respectively, 12 hours after dosing and 66.0%, 33.8%, and 1.9% of the radio-labeled dose was eliminated in the urine, bile, and feces, respectively, 24 hours after dosing. After 72 hours, 66.4%, 34.0%, 2.4%, and 0.3% of the of the radio-labeled dose had been found in the urine, bile, feces, and residual carcass, respectively. [Imidazopyridinyl-3-(14)C] Imazosulfuron was extensively metabolized. Metabolites HMS (56.9% of the dose), IHDU (4.9% of the dose), and HDS (0.5% of the dose) were excreted in the urine 24 hours after dosing. Metabolites HMS (3.8% of the dose), IHDU-glu (5.2% of the dose), HDS (1.6% of the dose), and ACIS (1.1% of the dose) were excreted in the bile 24 hours after dosing. Metabolite HMS (0.8% of the dose) was excreted in the feces 24 hours after dosing. From the identified metabolites, metabolic reactions determined to have occurred were demethylation, hydroxylation of the pyrimidine ring, methylation or glucuronidation of hydroxyl group, and opening of the pyrimidine ring and formation of guanidine.

Two test articles were used in this study: 1. [im-(14)C]imazosulfuon, specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0% together with unlabeled imazosulfuron, purity = 98.6% and 2. [pm-(14)C]imazosulfuon, specific activity 2.04 Gbq/mmol, radiochemical purity> 98.6% together with unlabeled imazosulfuron, purity = 98.6%, each of which was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 1 Crl:CD (SD) rat per sex. (14)C excretion into the expired air was negligible. Fecal and urine samples were collected at 1, 2, and 3 days after the administration of the dosing compounds. For [im-(14)C]imazosulfuon, 65.3% (male) and 69.0% (female) of radio-labeled dose was eliminated in the urine and 36.8% (male) and 31.8% (female) of the radio-labeled dose was eliminated in the feces 72 hours after dosing. For [pm- (14)C]imazosulfuon, 64.4% (male) and 57.9% (female) of radio-labeled dose was eliminated in the urine and 37.2% (male) and 40.1% (female) of the radio-labeled dose was eliminated in the feces 72 hours after dosing. Both [im-(14)C]imazosulfuon and [pm-(14)C]imazosulfuon were extensively metabolized. For [im-(14)C]imazosulfuon, metabolites HMS (54.6% of the dose in the male and 58.2% of the dose in the female) and IHDU (2.7% of the dose in the male and 4.3% of the dose in the female) were excreted in the urine 24 hours after dosing and metabolites HMS (6.9% of the dose in the male and 5.6% of the dose in the female), IHDU (0.8% of the dose in male and 0.3% of the dose in female), and ACIS (6.0% of the dose in the male and 4.3% of the dose in the female) were excreted in the feces 48 hours after dosing. For [pm-(14)C]imazosulfuon, metabolites HMS (50.3% of the dose in the male and 47.8% of the dose in the female) and IHDU (5.1% of the dose in the male and 3.1% of the dose in the female) were excreted in the urine 24 hours after dosing and metabolites HMS (5.3% of the dose in the male and 13.4% of the dose in the female), IHDU (0.7% of the dose in the male and 0.5% of the dose in the female), and UK-1 (3.8% of the dose in the male and 4.0% of the dose in the female) were excreted in the feces 48 hours after dosing. From the identified metabolites, metabolic reactions were determined to be demethylation, hydroxylation of the pyrimidine ring, opening of the pyrimidine ring, and hydrolysis of the sulfonylurea bridge.|[im- (14)C]imazosulfuron (specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0%) together with unlabeled imazosulfuron (purity = 98.6%) was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 4 male Crl:CD (SD) rats. Fecal and urine samples were collected at 6 and 12 hours (urine only), and 24, 48, and 72 days after the administration. 64.1% of radio-labeled dose was eliminated in the urine and 32.4% of the radio-labeled dose was eliminated in the feces 72 hours after dosing. The highest mean tissue concentrations of the radio-labeled dose were found in the carcass (0.15%), blood (0.04%), and liver (0.04%). [Imidazopyridinyl-3-(14)C] Imazosulfuron was extensively metabolized. Metabolites HMS (55.7% of the dose), IHDU (4.1% of the dose), and HDS (1.9% of the dose) were excreted in the urine 48 hours after dosing. Metabolites HMS (6.5% of the dose), IHDU (0.4% of the dose), HDS (2.3% of the dose), IPSN (2.9% of the dose, from extracts 1 and 3), and ACIS (3.2% of the dose from extracts 1 and 3) were excreted in the feces 48 hours after dosing. From the identified metabolites, metabolic reactions were determined to be demethylation, hydroxylation, methylation of the hydroxyl group, opening of the pyrimidine ring, and hydrolysis of the sulfonylurea bridge.|[im-(14)C]Imazosulfuron (specific activity 2.15 Gbq/mmol, radiochemical purity> 99.0%) together with unlabeled imazosulfuron (purity = 98.6%) was suspended in 0.5% carboxymethyl cellulose in ultrapure water and administered in a single dose by gavage to 3 bile duct-cannulated male Crl:CD (SD) rats. Feces, bile, and urine samples were collected at 6 and 12 hours (urine and bile only), and 24, 48, and 72 hours after the administration of the dosing material. 53.4% and 30.5% of the radio-labeled dose was eliminated in the urine and bile, respectively, 12 hours after dosing and 66.0%, 33.8%, and 1.9% of the radio-labeled dose was eliminated in the urine, bile, and feces, respectively, 24 hours after dosing. After 72 hours, 66.4%, 34.0%, 2.4%, and 0.3% of the of the radio-labeled dose had been found in the urine, bile, feces, and residual carcass, respectively. [Imidazopyridinyl-3-(14)C] Imazosulfuron was extensively metabolized. Metabolites HMS (56.9% of the dose), IHDU (4.9% of the dose), and HDS (0.5% of the dose) were excreted in the urine 24 hours after dosing. Metabolites HMS (3.8% of the dose), IHDU-glu (5.2% of the dose), HDS (1.6% of the dose), and ACIS (1.1% of the dose) were excreted in the bile 24 hours after dosing. Metabolite HMS (0.8% of the dose) was excreted in the feces 24 hours after dosing. From the identified metabolites, metabolic reactions determined to have occurred were demethylation, hydroxylation of the pyrimidine ring, methylation or glucuronidation of hydroxyl group, and opening of the pyrimidine ring and formation of guanidine.

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

/CASE REPORTS/ The development of discolored urine may have many possible causes. Here we present the case of a 76-year-old woman who was admitted after ingesting the inorganic herbicides, mefenacet and imazosulfuron. Her urine color changed to green almost immediately. Since the patient had no specific medication or medical history we considered that the most likely cause of the change in urine color was the ingestion of the herbicides. Spectrophotometric analysis of the urine was conducted and a peak was observed in the green area of the wavelength spectrum. These findings show that mefenacet and imazosulfuron should be considered in the differential diagnosis of green discolored urine.

1-(2-chloroimidazo(1,2-a)pyridin-3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2-yl)urea

Imazosulfuron Technical (Valent U.S.A. LLC): Active ingredient: imazosulfuron 99.5%.|V-10142 Herbicide (Valent U.S.A. LLC): Active ingredient: imazosulfuron 75.0%.|V-10142 AG Herbicide (Valent U.S.A. LLC): Active ingredient: imazosulfuron 75.0%.|League MVP Herbicide (Valent U.S.A. LLC): Active ingredient: thiobencarb 10.0% and imazosulfuron 0.43%.|Granule, suspension concentrate, water dispersible granule.

Adequate enforcement methodology (high performance liquid chromatography method with tandem mass spectroscopy detection (LC/MS/MS)) is available to enforce the tolerance expression.|A liquid chromatographic (LC) method with diode array detection (DAD) was developed for screening of 10 sulfonyl urea herbicide residues in unpolished rice. The investigated herbicides were azimsulfuron, bensulfuron-methyl, chlorimuron-ethyl, chlorsulfuron, ethoxysulfuron, flazasulfuron, imazosulfuron, metsulfuron-methyl, pyrazosulfuron-ethyl and tribenuron-methyl. Acetonitrile-water (2:1) extracts of rice samples were cleaned up with solid-phase extraction cartridges (octadecylsilane-bonded silica (ODS) and graphitized carbon black (GCB)). Three fractions of the GCB eluate were taken for analysis using 3 separate injections in order to avoid interference in LC-DAD analysis and to reduce analyte coelution problems. Recoveries from rice samples fortified with the 10 herbicides at 0.05 and 0.2 ug/g ranged from 46.6 to 119.6%, and coefficients of variation were 3.1-12.6%. The quantitation limits were 0.01-0.02 ug/g.|Reversed-phase liquid chromatography (LC) is used to determine a relatively new sulfonylureic herbicide, imazosulfuron, 1-(2-chloroimidazo-[1,2-a] pyridin-3-ylsulfonyl)-3-(4,6-dimethoxy-2-pyrimidinyl)-urea (TH-913), in drinking water and in soil. TH-913 is extracted from water using solid-phase extraction on C18 bonded silica. Soil samples (20 g) are extracted with 300 mL of methanol-water (50:50) and the acidified extracts are transferred onto Sep-Pak C18 and processed as described for water samples. Off-line desorption is done with 20 mL of methanol-water (50:50). The eluate is evaporated to dryness, the residue dissolved in acetonitrile and analyzed by LC with UV detection at 238 nm. The recoveries of TH-913 from water were over 95% (at 0.05 ug/L level) and from soil over 90% (at 0.005 mg/kg level).|LC /liquid chromatography/ determination in water and soil.

Agrochemicals -> Herbicides