Prosulfuron

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: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Methods and materials for containment and cleaning up: Pick up and arrange disposal without creating dust. Sweep up and shovel. Keep in suitable, closed containers for disposal.

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.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Precautions for safe handling: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Provide appropriate exhaust ventilation at places where dust is formed.

Appropriate engineering controls: Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

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.

Tolerances are established for residues of prosulfuron, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only prosulfuron (N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]-2-(3,3,3-trifluoropropyl)benzenesulfonamide) in or on the commodity.[Table#8528]

Eye/face protection: Safety glasses with side-shields conforming to EN166. 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: Complete suit protecting against chemicals. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Respiratory protection: For nuisance exposures use type P95 (US) or type P1 (EU EN 143) particle respirator. For higher level protection use type OV/AG/P99 (US) or type ABEK-P2 (EU EN 143) respirator cartridges. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

LC50; Species: Colinus virginianus (Northern Bobwhite Quail) age 11 days; diet >5000 ppm for 8 days /99.1% purity/

LC50; Species: Anas platyrhynchos (Mallard Duck) age 5 days; diet >5000 ppm for 8 days /99.1% purity/

LD50; Species: Colinus virginianus (Northern Bobwhite Quail) age 37 weeks; oral via capsule >2150 mg/kg /99.1% purity/

LD50; Species: Anas platyrhynchos (Mallard Duck) age 20 weeks; oral via capsule 1094 mg/kg /99.2% purity/

For more Ecotoxicity Values (Complete) data for Prosulfuron (15 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), a measured Koc range of 4-251(2), indicates that prosulfuron is expected to have very high to moderate mobility in soil(SRC). A pKa of 3.76(2) indicates prosulfuron will exist partially in anion form at pH 5 and almost entirely in anion form at pH 6-9(SRC). Sorption studies found that anion exchange of prosulfuron accounted for up to 82% of overall sorption in the pH range of 3 to 7(3); humic acid and anion-cation exchange capacities of the soil can effect the Koc(3). Volatilization of non-ionized prosulfuron from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of <5.0X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, <2.63X10-8 mm Hg(2), and water solubility, 87-43000 mg/L at pH 5-7.7(2). Prosulfuron in anion form will not volatilize. Prosulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(SRC). Volatilization from soil and plant surfaces has been measured as negligible(4). Results of degradation studies indicate that prosulfuron is not readily biodegradable(4). Sterile versus non-sterile soil degradation tests have demonstrated that microbial degradation can be an important fate in soil, especially in the absence of abiotic hydrolysis(5). Prosulfuron is susceptible to aqueous hydrolysis in moist acidic soils; hydrolysis half-life has been reported as 5-12 days at pH 5 and 25 °C(4). Field dissipation half-lives of 3.9-38.9 days and 4-36 days have been reported(2,4).

AQUATIC FATE: Based on a classification scheme(1), a Koc range of 4-251(2), indicates that prosulfuron is not expected to adsorb to suspended solids and sediment(SRC). A pKa of 3.76(2) 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 non-ionized form(3) based upon an estimated Henry's Law constant of <5.0X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, <2.63.5X10-8 mm Hg(2), and water solubility, 87-43000 mg/L at pH 5-7.7(2). According to a classification scheme(4), an estimated BCF of 1(SRC), from its log Kow of 1.50(2) and a regression-derived equation(5), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Results of degradation studies indicate that prosulfuron is not readily biodegradable(6). Dissipation half-life in four water-sediment systems (pond and river water) ranged from 119-216 days with a geometric mean of 173 days(6). Prosulfuron is susceptible to hydrolysis at pH 5, but stable to hydrolysis at pH 7 and pH 9(7). The hydrolysis half-life at pH 5 (25 °C) is 5-12 days(6); hydrolysis half-lives at pH 7 and pH 9 are 424-651 days and 682-1690 days respectively(6). Photodegradation studies in water indicate direct photolysis is not an important fate process(6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), prosulfuron, which has a vapor pressure of <2.63X10-8 mm Hg at 25 °C(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase prosulfuron may be removed from the air by wet and dry deposition(SRC). Photodegradation studies in water indicate direct photolysis is not an important fate process(3).

IDENTIFICATION AND USE: Prosulfuron is a triazinyl-sulfonylurea herbicide. HUMAN STUDIES: There are no data available. ANIMAL STUDIES: It is not skin or eye irritant, or sensitizer. In a subchronic oral toxicity study, prosulfuron technical was administered to 4 beagle dogs/sex/dose via the diet at dose levels of 0, 15, 150, 1500, or 3000 ppm for 90 days. Hematotoxicity was observed in both sexes. Hepatotoxicity was observed in both sexes at the two highest dose levels. At the highest dose tested, two males displayed myocardial necrosis with fibrosis and dystrophic mineralization in the ventricular and papillary muscles, and one female displayed myocardial degeneration. A 90-day feeding study in mice was conducted in which prosulfuron was administered orally to mice at dietary levels of 0, 15, 500, 1750, 3500, or 7000 ppm. At higher dose levels, degenerative vacuolation of the heart was observed in males at > 3500 ppm and in females at 7000 ppm. The incidence of centrilobular hypertrophy observed in the liver was statistically significant at > 1750 in males and > 3500 in females. In a carcinogenicity study in rats, groups of 60 rats/sex/dose group were administered 0, 10, 200, 2000 or 4000 ppm in the diet for a 2-year period. Increases in the incidence of mammary adenocarcinomas in females was observed at 2000 ppm and 4000 ppm compared to controls. Mammary gland adenomas were also slightly increased at 2000 ppm and 4000 ppm. Slight increases in the incidence of benign testicular interstitial cell tumors (significant trend only) were also observed at 2000 ppm and 4000 ppm compared to controls. In a feeding carcinogenicity 18-month study in mice there was no increase in the incidence of neoplasia in treatment groups when compared to controls. In a developmental study in rabbits fetal weights were reduced and skeletal anomalies/delayed ossification increased. In a neurotoxicity study in rats the observed effects were consistent with transient neurotoxicity affecting primarily sensorimotor and gait functions. Mutagenicity tests were negative. ECOTOXICITY STUDIES: In combination with other triazinyl-sulfonylurea herbicides it exerted a detrimental effect on soil microbial biomass and its biochemical activities.

/OTHER TOXICITY INFORMATION/ Soil microcosm experiments were used to investigate the effects on growth and activity of soil microorganisms of an herbicide combination (60% bromoxynil + 3% prosulfuron) frequently used to provide a broad spectrum control of weed species. Culturable aerobic bacteria, fungi, and actinomycetes, the fundamental groups of heterotrophic microorganisms, and nitrifiers, considered a very sensitive group to these compounds, were evaluated. Since herbicides have been found to inhibit decomposition of cellulose in soil, the effects on cellulolytic bacteria and fungi were determined. Dehydrogenase activity as a measure of microbial activity was another parameter considered. The results emphasized a tendency of reversible stimulatory/inhibitory effects of the tested compounds on soil microorganisms, with fungi as an exception. A long-lasting negative action on the activity of the dehydrogenase (DHA), commonly used as an index of the overall microbial activity in soil, was found. The magnitude of these effects were dependent on the assayed concentrations of the herbicides mixture. ...The presence of bromoxynil + prosulfuron could induce significant changes in the microbial populations of the soil, concerning the activity and balance of microbial community. Possible environmental risks must be considered. Dehydrogenase activity was shown to be an important indicator of side-effects attributed to these herbicides.

/OTHER TOXICITY INFORMATION/ The effect of four triazinyl-sulfonylurea herbicides (cinosulfuron, prosulfuron, thifensulfuron methyl, triasulfuron) on soil microbial biomass, soil respiration, metabolic activity, metabolic quotient, and some enzymatic activities (acid and alkaline phosphatase, beta-glucosidase, arylsulphatase, and fluorescein diacetate hydrolysis) were monitored under controlled conditions over 30 days. The herbicides were applied at the normal field dose (FD) and at ten-fold (10 FD) the field dose, in order to mimic a long term toxic effect. The measured soil microbial parameters showed that the FD had slight effects on soil microflora, while at 10 FD the tested herbicides exerted a stronger detrimental effect on soil microbial biomass and its biochemical activities.

EPA has released the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The iCSS Dashboard provides an interactive tool to explore rapid, automated (or in vitro high-throughput) chemical screening data generated by the Toxicity Forecaster (ToxCast) project and the federal Toxicity Testing in the 21st century (Tox21) collaboration. /The title compound was tested by ToxCast and/or Tox21 assays/[USEPA; ICSS Dashboard Application; Available from, as of August 9, 2018: http://actor.epa.gov/dashboard/]

Based Freundlich Kfoc (organic carbon normalized Freundlich adsorption coefficient), batch sorption studies in 8 different soils (organic carbon content 0.36-19.34%) determined a Koc range of 3.9-37.3 and an arithmetic Koc mean of 14.2(1). A measured Koc range of 4-251 has also been reported(2). According to a classification scheme(3), these Koc ranges suggest that prosulfuron is expected to have very high to moderate mobility in soil. A pKa of 3.76(2) indicates prosulfuron will exist partially in anion form at pH 5 and almost entirely in anion form at pH 6-9(SRC). Tests using various sorbents and 10 variable-charge soil types found that anion exchange of prosulfuron accounted for up to 82% of overall sorption in the pH range of 3 to 7(4); humic acid and anion-cation exchange capacities of the soil can effect the Koc(4).

Prosulfuron's production may result in its release to the environment through various waste streams; its use as a post-emergence herbicide for broad spectrum control in maize, sorghum, cereals, pasture and turf(1) will result in its direct release to the environment(SRC).

AEROBIC: Results of degradation studies indicate that prosulfuron is not readily biodegradable(1). Dissipation half-life in four water-sediment systems (pond and river water) ranged from 119-216 days with a geometric mean of 173 days(1). In prosulfuron transformation studies in three soil-waters (unsterilized versus sterilized conditions), the initial half-life in one soil-water (pH 7.2) was 24.05 days in unsterilized soil and 52.5 days in sterilized soil indicating microbial activity(2); in the other two soil-waters (pH 4.9, pH 5.9), degradation rates were similar and faster in both unsterile and sterile conditions due to abiotic hydrolysis in acidic media(2).

AEROBIC: Laboratory soil dissipation half-lives of prosulfuron at 20 °C ranged from 15.4-229 days with a geometric mean of 62.1 days(1). A compilation of 11 field studies lists a prosulfuron dissipation half-life of 3.8-38.9 days (average of 11.9 days)(1). A field dissipation half-life of 4-36 days is also reported, with the rate depending on temperature, soil moisture and organic content(2). Field dissipation of 90% is reported to range from 14-120 days with a typical value of 60 days(2).

An estimated BCF of 1 was calculated in fish for prosulfuron(SRC), using a log Kow of 1.50(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).

A pKa of 3.76(1) indicates prosulfuron 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 prosulfuron will not be an important fate process(SRC). The Henry's Law constant for non-ionized prosulfuron is estimated as <5.0X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, <2.63X10-8 mm Hg(1), and water solubility, 87-43000 mg/L at pH 5-7.7(1). This Henry's Law constant indicates that non-ionized prosulfuron is expected to be essentially nonvolatile from water surfaces(2). Prosulfuron's estimated Henry's Law constant and ionization indicates that volatilization from moist soil surfaces is not expected to occur(SRC). Prosulfuron is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. Volatilization from soil and plant surfaces has been measured as negligible(3).

Tolerances are established for residues of prosulfuron, including its metabolites and degradates, in or on the commodities in the table below. Compliance with the tolerance levels specified below is to be determined by measuring only prosulfuron (N-[[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)amino]carbonyl]-2-(3,3,3-trifluoropropyl)benzenesulfonamide) in or on the commodity.[Table#8529]

EPA has completed a quantitative human health risk assessment and a quantitative ecological risk assessment of the 22 SU /sulfonylurea/ herbicides /including prosulfuron/. The Agency determined that there are no human health risks of concern at this time. The Agency also determined that there are no direct ecological risks of concern to taxa, except non-target terrestrial and aquatic plants, at this time. ... Based upon a lack of data, the Agency has not fully assessed potential risk from SU herbicides to terrestrial invertebrates. In the future, the Agency will consider requiring additional pollinator data and fully evaluate risk to insect pollinators. The Agency is requiring certain changes to the product specific labeling to reduce potential risk to non-target plants from spray drift. ... In this Interim Registration Review Decision for the SU herbicides, EPA is making no human health or environmental safety findings associated with the EDSP screening, risk to pollinators, nor is it making a complete endangered species finding. The Agency's final registration review decision for these 22 SU herbicides will be issued once an effects determination for listed species is made, and ESA Section 7 consultation with the Services has taken place, if necessary; an EDSP FFDCA section 408(p) determination has been made; and a pollinator risk assessment has been completed.

For prosulfuron (USEPA/OPP Pesticide Code: 129031) ACTIVE products with label matches. /SRP: Registered for use in the USA but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Prosulfuron is a selective herbicide used post-emergence on maize, sorghum, cereals (field corn, white corn, popcorn), pasture, and turf for broad-spectrum control of annual broad-leaved weeds.

Herbicide

Prosulfuron is produced by reaction of 2- (3,3,3-trifluoropropyl)phenylsulfamoylchloride with 2-amino-4-methyl-6-methoxypyrimidine.

Preparation: W. Meyer, K. Oertle, European Patent Office patent 120814; eidem, United States of America patent 4671819 (1984, 1987 both to Ciba-Geigy)

Halosulfuron methyl 50%/Prosulfuron 29% WDG (Canyon Group LLC): Active ingredient: halosulfuron-methyl 50.0% and prosulfuron 29.0%.

Peak (Syngenta Crop Protection, LLC): Active ingredient: prosulfuron 57.0%.

Prosulfuron Technical (Syngenta Crop Protection, LLC): Active ingredient: prosulfuron 96.0%.

Spirit Herbicide (Syngenta Crop Protection, LLC): Active ingredient: primisulfuron-methyl 42.8% and prosulfuron 14.2%.

For more Formulations/Preparations (Complete) data for Prosulfuron (6 total), please visit the HSDB record page.

Herbicides

Environmental transformation -> Pesticides (parent, predecessor)