Carfentrazone-ethyl

Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.

Wear self contained breathing apparatus for fire fighting if necessary.

Wear respiratory protection. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas...

Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided.

Soak up with inert absorbent material and dispose of as hazardous waste. 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.

For End-Use Products the following language should be stated: "Carfentrazone-ethyl is very toxic to aquatic plants and moderately toxic to fish. Do not apply directly to water, to areas where surface water is present or to intertidal areas below the high water mark, except as specified on this label. Do not contaminate water when disposing of equipment washwaters."

For Manufacturing-use products the following language should be stated: "Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or public waters unless this product is specifically identified and addressed in an NPDES permit. Do not discharge effluent containing this product to sewer systems without previously notifying the sewage treatment plant authority. For guidance, contact your State Water Board or Regional office of the EPA."

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.

Avoid contact with skin and eyes. Avoid inhalation of vapor or mist.

Tolerances are established for residues of the herbicide carfentrazone-ethyl, including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the following tolerance levels is to be determined by measuring only the sum of carfentrazone-ethyl (ethyl-alpha-2-dichloro-5-[-4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H -1,2,4-triazol-1-yl]-4-fluorobenzenepropanoate) and its metabolite carfentrazone-chloropropionic acid (alpha, 2-dichloro-5-[-4-difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-fluorobenzenepropanoic acid), calculated as the stoichiometric equivalent of carfentrazone-ethyl, in or on the following commodities:[Table#6854]

Face shield and safety glasses. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166 (EU).

Handle with gloves.

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.

Where risk assessment shows air-purifying respirators ar appropriate use a full-face respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Carfentrazone-ethyl is not considered to cause significant toxicity in helathy humans. But in patient with very large acute exposures or long-term chronic exposures, carfentrazone-ethyl may cause variegate porphyria or transient porphyria cutanea tarda-like syndrome. (L2125)

LC50; Species: /Colinus virginianus/ (Bobwhite quail) dietary >5620 ppm for 8 days

LD50; Species: Colinus virginianus (Northern bobwhite) age 16 wk; oral >2250 mg/kg[USEPA, Office of Pesticide Programs; Pesticide Ecotoxicity Database (2000) on alpha,2-Dichloro-5-

LC50; Species: Anas platyrhynchos (Mallard Duck) age 10 days; diet >5620 ppm for 8 days

LD50; Species: /Apis mellifera/ (Bee) contact >200 ug/bee

For more Ecotoxicity Values (Complete) data for CARFENTRAZONE-ETHYL (16 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), Koc values of 15-35 at pH 5.5 and 750 (pH not specified)(2) indicate that carfentrazone-ethyl is expected to have very high mobility in acid soil and low mobility in neutral or basic soils(SRC). Volatilization of carfentrazone-ethyl from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.0X10-9 atm-cu m/mole(SRC), based upon its vapor pressure, 1.2X10-7 mm Hg(2), and water solubility, 22 mg/L(2). Carfentrazone-ethyl is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(2). Measured half-lives of carfentrazone-ethyl in Beijing and Jilin, China soil samples collected during a wheat field dissipation study were reported as 5.8 and 3.8 hours, respectively(3). The route of dissipation was not reported(3), however, based on other field studies, chemical hydrolysis is expected to be the primary route of degradation(4-5). These degradation rates indicating that biodegradation is not expected to compete with the hydrolysis of carfentrazone-ethyl, especially under neutral or basic conditions(4-5).

TERRESTRIAL FATE: Dissipation and residues of carfentrazone-ethyl were measured after field application in Beijing and Jilin, China, at respective rates of 120 and 600 g/100 sq m (g/hm2)(1). The half-life for carfentrazone-ethyl was 5.8 and 3.8 hours at the respective locations(1).[Table#6855]

AQUATIC FATE: Based on a classification scheme(1), a Koc value of 750(2) indicates that carfentrazone-ethyl is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 3.0X10-9 atm-cu m/mole(SRC), derived from its vapor pressure, 1.2X10-7 mm Hg(2), and water solubility, 22 mg/L(2). Carfentrazone-ethyl had reported hydrolysis half-lives of 131 and 3.4 hours at respective pH values of 7.09 and 9.09(4). Only 43% of the substance was hydrolyzed after 830 hours at pH 5.17(4). According to a classification scheme(5), an estimated BCF of 77(SRC), from its log Kow of 3.36(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). The half-lives of carfentrazone-ethyl in the water layer above aquatic sediments ranged from 1.0-1.5 days in a separate study(7). Chemical hydrolysis was the primary route of degradation, indicating that biodegradation is not expected to compete with the hydrolysis of carfentrazone-ethyl, especially under neutral or basic conditions(4,7).

AQUATIC FATE: The degradation of radio labeled carfentrazone-ethyl was tested in flooded sediment (silty clay loam and clay loam soils)(1). Following application to the water layer, the radioactivity slowly transferred to the sediment layer. Percent radioactivity in the aqueous layers fell from 83-90% at zero time to 70-80% after 30 days while percent radioactivity in the soil layers rose from 4-6% at day zero to 13-19% after 30 days. primary degradation pathway was chemical hydrolysis to carfentrazone-chloropropionic acid which is then further degraded to carfentrazone -cinnamic, -propionic, -benzoic and 3-(hydroxymethyl)-carfentrazone-benzoic acids. The concentration of radio-labeled carfentrazone-ethyl (CF-E) and its major degradation product, carfentrazone-chloropropionic acid (CF-CIPAc), are reported below in two types of soil(1).[Table#6856]

For more Environmental Fate (Complete) data for CARFENTRAZONE-ETHYL (6 total), please visit the HSDB record page.

IDENTIFICATION AND USE: Carfentrazone-ethyl is a viscous yellow-orange liquid with a faint petroleum odor. It is registered for pesticide use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses. It is used as a postemergent, contact herbicide for controlling broadleaf weeds; as a defoliant in cotton; and it provided a good control of hazelnut shoots. It is also used for turf and ornamentals. HUMAN EXPOSURE AND TOXICITY: There is no published data available on the toxicity in humans. ANIMAL STUDIES: Ninety-day subchronic feeding studies resulted in decreases in body weight, reductions in food consumption and histopathological lesions in rats; liver pathology in mice; and decrease in the rate of weight gain in females and an increase in urinary porphyrins in both sexes of dogs. Carfentrazone-ethyl was found to be non-carcinogenic when administered for 18 months to mice at dietary intake doses of 0, 10, 110 and 1090 mg/kg/day for males and 0, 12, 119 and 1296 mg/kg/day for females and in a 2-year rat chronic toxicity/carcinogenicity study conducted in rats at intake levels of 0, 2, 9, 37 and 188 mg/kg/day for males and 0, 3, 12, 49 and 242 mg/kg/day for females. A developmental toxicity study in rabbits was conducted at gavage dose levels of 0, 10, 40, 150 and 300 mg/kg/day. Evidence of treatment-related maternal toxicity consisted of unthriftiness and emaciation in two does at 300 mg/kg/day. There were no treatment-related mortalities or gross pathological findings. No effects on body weight, body weight change, or organ weight data were identified at any treatment level. A two-generation reproduction study in the rat was conducted with dietary levels of 0, 8.6, 42.4, 127, 343 mg/kg/day for males, and 0, 9.5, 47.8, 142, and 387 mg/kg/day for females. There was no systemic toxicity demonstrated at dose levels of less than/equal to 1500 ppm. There were no treatment related clinical signs of toxicity or increases in mortality at any dose levels. There were no clinical signs of toxicity reported for the pups of either generation. Carfentrazone-ethyl was negative for genotoxicity in two reverse gene mutation assays (Salmonella typhimurium), both with and without metabolic activation. Mammalian cell forward gene mutation assay in CHO cells in vitro yielded negative results both with and without activation. An in vitro chromosomal aberration assay yielded positive results under non-activated conditions following doses of 3.75, 12.5, 37.5 and 125 ug/mL. There were consistent and statistically significant increased incidences of cells with aberrations at 125 ug/mL, the highest dose tested in the absence of metabolic activation.

EPA has released the first beta version (version 0.5) of the Interactive Chemical Safety for Sustainability (iCSS) Dashboard. The beta version of 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; Click on the "Chemical Explorer" button on the tool bar to see the data./[USEPA; ICSS Dashboard Application; Available from, as of April 22, 2015: http://actor.epa.gov/dashboard/]

A Koc value of 750 (pH not specified) and 15-35 at pH 5.5 have been reported(1). According to a classification scheme(2), these Koc values suggest that carfentrazone-ethyl is expected to have very high mobility in acid soil and low mobility in neutral or basic soils(SRC).

AEROBIC: The half-life for the aerobic metabolism of carfentrazone-ethyl in soil has been reported as 1.3 days(1).

ANAEROBIC: The half-life for the anaerobic metabolism of carfentrazone-ethyl in water has been reported as 0.3-0.8 days(1). Additional details were not provided.

Tolerances are established for residues of the herbicide carfentrazone-ethyl, including its metabolites and degradates, in or on the commodities listed in the following table. Compliance with the following tolerance levels is to be determined by measuring only the sum of carfentrazone-ethyl (ethyl-alpha-2-dichloro-5-[-4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H -1,2,4-triazol-1-yl]-4-fluorobenzenepropanoate) and its metabolite carfentrazone-chloropropionic acid (alpha, 2-dichloro-5-[-4-difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-fluorobenzenepropanoic acid), calculated as the stoichiometric equivalent of carfentrazone-ethyl, in or on the following commodities:[Table#6857]

Registration Review Decision and Begin Post-Decision Follow-up: Estimated Date: 2018.

Pesticide Fact Sheet: Name of Chemical: Carfentrazone-ethyl; Reason for Issuance: New Chemical Registration; Date Issued: September 30, 1998.