Topramezone

363.39

363.39

606-699-4

W4934JAQ65

DTXSID0034722

Light beige liquid

114

1.44 (est)

1.13 g/cu cm at 20 deg C

590.5±60.0 °C at 760 mmHg

310.9±32.9 °C

1.670

In water, 305 mg/L at 25 deg C (est)

Store in the original container until ready to use. Store in a cool, dry location away from food or feedstuffs. Keep away from children. /Impact/

3.8X10-12 mm Hg at 25 deg C (est)

Aromatic

Henry's Law constant = 9.4X10-18 atm-cu m/mol at 25 °C (est)

pKa1 = 4.28; pKa2 = 7.34 (phenol on heterocyclic) (est)

Hydroxyl radical reaction rate constant = 1.4X10-11 cu cm/molec-sec at 25 °C (est)|Chemical/physical properties of technical Topramezone. [Table#7179]|UV/visible absorption spectrum: 207 nm (epsilon = 27 077/mol-cm); 272 (epsilon 8601/mol-cm); 300 nm (epsilon 5800/mol-cm); 410 nm (epsilon 410/mol-cm) /Technical product/|BP: Approx 100 °C. MP: approximately -4 °C. Evaporation rate: 1.0 (as water). Vapor pressure is equal to water evaporation. Percent volatile by vol: approximately 70%. ... Stable under normal storage conditions. /Technical product/

UN30779/PG3

1

61-50/53

53-45-60-61

T,N

P201-P273-P308 + P313-P501

H360-H410

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. 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 soil or water; effects on animal, aquatic, and plant life; and conformance with environmental and public health regulations.

U.S. Environmental Protection Agency, Office of Prevention, Pesticides and Toxic Substances. Pesticide Fact Sheet for Topramezone (August 2005). Available from http://www.epa.gov/opprd001/factsheets/index.htm#N as of February 28, 2007

|Danger|H360 (100%): May damage fertility or the unborn child [Danger Reproductive toxicity]|P201, P202, P273, P281, P308+P313, P391, P405, and P501|Aggregated GHS information provided by 225 companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H360: May damage fertility or the unborn child [Danger Reproductive toxicity]|P201, P202, P260, P281, P308+P313, P314, P405, and P501

EXPOSURE CONTROLS/PERSONAL PROTECTION ENGINEERING CONTROLS: It is recommended that all mixing be done in a well ventilated area. RESPIRATORY PROTECTION: If a well ventilated area is not available during mixing or application, it may be necessary to use an OSHA approved respirator fitted with organic vapor cartridges. SKIN PROTECTION: Persons working with this product should wear a long-sleeved shirt, trousers, shoes, and a hat. Hands should be protected by chemical resistant gloves, such as nitrile. All clothing should be washed prior to reuse. EYE PROTECTION: Safety glasses, with sideshields, are required whenever someone is working with potentially hazardous chemicals. If there is a possibility of splashing or misting, safety goggles and/or a full faceshield are required. OTHER PROTECTION: An eyewash station should be available whenever persons are working with potentially hazardous chemicals. /Impact/

EXTINGUISHING MEDIA: Water spray, foam, carbon dioxide (CO2), dry extinguishing media. FIRE FIGHTING INSTRUCTIONS: Keep bystanders away. Wear full bunker gear, including selfcontained breathing apparatus. Collect contaminated water and dispose of water and debris in accordance with local regulations. /Impact/

SMALL SPILL: Cover with absorbent (clay, sawdust, straw, kitty litter, etc.), to absorb the liquid. Sweep into an open drum. Clean the area with common powdered household detergent and a stiff brush and just enough water to make a slurry. Absorb and sweep into the same open drum. Rinse with water, absorb, and add to the waste drum. Close the drum and dispose of properly. LARGE SPILL: Dike the spill to prevent contamination of local water sources. Siphon the majority of the liquid into drums for use or disposal, depending on the circumstances. Clean the area as described for a small spill. /Impact/

... NOTE TO PHYSICIANS: Treat according to the symptoms observed (decontamination, vital functions). There is no know specific antidote for the components in this product. /Impact/|FIRST AID MEASURES: EYES: Immediately flush the eyes with copious amounts of clear, cool running water for a minimum of 15 minutes. Hold the eyelids apart during the flushing to ensure rinsing of the entire surface of the eyes and lids with water. Contact a physician immediately. If there will be a delay in getting medical attention, rinse the eyes for at least another 15 minutes. SKIN: Immediately flush all affected areas with large amounts of clear water for at least 15 minutes. Remove contaminated clothing. Do not attempt to neutralize with chemical agents. Wash clothing before reuse. If skin irritation develops, contact a physician immediately. /Impact/|HANDLING: Wear personal protective equipment when handling this product. Do not eat, drink or smoke when using this product. Wash thoroughly after handling this product. /Impact/

Topramezone has a low acute toxicity via the oral, dermal, or inhalation route. It is a slight eye and dermal irritant, and it is not a skin sensitizer. Following oral administration, topramezone is rapidly absorbed and excreted via urine and feces. Topramezone is an inhibitor of 4-hydroxyphenylpyruvate dioxygenase (4-HPPD); this results in elevated serum tyrosine levels. However, no data could determine at what level increases of tyrosine levels would result in detrimental (adverse) effects. As a consequence of the elevated tyrosine levels, topramezone has been shown to cause adverse effects in the eye, liver, kidney, pancreas, and thyroid. Histopathological evaluations showed dose-dependent increases of adverse effects in the thyroid (follicular cell hyperplasia) in rats and dogs, pancreas (diffuse degeneration) in rats, liver (hepatocellular hypertrophy and focal necrosis) in rats and mice, and eyes (chronic keratitis) in rats. The reproductive toxicity study in rats did not demonstrate adverse reproductive effects; however, developmental toxicity studies in rats and rabbits showed increased incidences of skeletal variation and alterations in skeletal ossification sites. Animal studies show that skeletal variations are associated with 4-HPPD inhibitor herbicides (mesotrione and isoxaflutole). Mutagenicity studies conducted on technical topramezone and its major metabolites did not demonstrate any mutagenic potential. Increased incidences of thyroid follicular cell adenomas and adenoma and/or adenocarcinomas combined were observed in the carcinogenicity study in rats of both sexes. In accordance with the EPA Final Guidelines for Carcinogen Risk Assessment (March 29, 2005), the /EPA Health Effects Division (HED)/ classified topramezone as "not likely to be carcinogenic to humans at doses that do not alter rat thyroid hormone homeostasis". HED determined that quantification of human cancer risk is not required since the NOAEL (0.4 mg/kg/day) for non-cancer risk assessment is not expected to alter thyroid hormone homeostasis nor result in thyroid tumor formation.

/BIRDS and MAMMALS/ Topramezone is practically nontoxic to /avian and mammalian species/ ... Chronic effects for bobwhite quail reproduction include reduction in the ratio of number hatched to live embryos (a measure of hatchability) at the highest treatment level, 1012 mg ai/kg dw and the mallard duck reproduction had significant reductions in hatchling body weight and female weight gain at all three treatment levels, resulting in the inability to define a NOAEC. No chronic effects were observed in mammals as high as 4000 ppm, based on a two-generation toxicity study on laboratory rats. ...|/AQUATIC SPECIES/ Topramezone is practically nontoxic to ... freshwater fish and invertebrates and estuarine/marine fish and moderately toxic to estuarine/marine invertebrates. ... Chronic effects were apparent for freshwater fish with reduced growth (length and weight) at 9.01 mg aiL-1. Estimated chronic effects for estuarine/marine fish are uncertain because no chronic data were submitted by the registrant; the NOAEC value was derived based on the assumption that the freshwater and estuarine/marine fish are of equal sensitivity. M670H05 is practically nontoxic to freshwater fish and invertebrates. The formulated product Topramezone SC is practically nontoxic to ... freshwater fish and invertebrates.|/OTHER TERRESTRIAL SPECIES/ Overall, topramezone is practically nontoxic to ... honeybees /and/ earthworms ... The formulated product Topramezone SC is practically nontoxic to honeybee and/ terrestrial invertebrates ...|/PLANTS/ Toxic effects were higher on vascular than on non-vascular plants. Vascular plants are more sensitive to topramezone (TGAI) than to M670H05 (metabolite) or to Topramezone SC (formulated topramezone). The most pronounced effects on frond counts were observed for topramezone TGAI. No tests were conducted with "M670H01" or "M670H10", which may exhibit herbicidal activity. All terrestrial plants showed toxic effects in seedling emergence and vegetative vigor studies, but at varying degree depending on the species and exposure concentrations. In seedling emergence and vegetative vigor studies, monocots were observed to be less sensitive than dicots. The most sensitive plants to seedling emergence were ryegrass (monocot) and cabbage (dicot). The most sensitive plants to vegetative vigor were onion (monocots) and soybeans (dicots). Dry weight was selected as the most sensitive endpoint. However, phytotoxic effects and other growth effects such as shoot height were also observed.

Topramezone's production may result in its release to the environment through various waste streams; its use as a herbicide(1) will result in its direct release to the environment(SRC). Drift and runoff have been identified as possible routes leading to residues entering aquatic ecosystems(1).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 140(SRC), determined from an estimated log Kow of 1.44(2) and a regression-derived equation(3), indicates that topramezone is expected to have high mobility in soil(SRC). Volatilization of topramezone from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 9.4X10-18 atm-cu m/mole(SRC), using a fragment constant estimation method(4). Topramezone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.8X10-12 mm Hg(SRC), determined from a fragment constant method(5). A biodegradation half-life in soil of >125 days(6) suggests that biodegradation is not an important environmental fate process in soil(SRC).|AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 140(SRC), determined from an estimated log Kow of 1.44(2) and a regression-derived equation(3), indicates that topramezone is not 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 9.4X10-18 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). According to a classification scheme(5), an estimated BCF of <0.3(SRC), from an estimated log Kow(2) and a regression-derived equation(6), suggests the potential for bioconcentration in aquatic organisms is low(SRC). A biodegradation half-life in soil of >125 days(7) suggests that biodegradation is not an important environmental fate process in water(SRC).|ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), topramezone, which has an estimated vapor pressure of 3.8X10-12 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Topramezone is not expected to be susceptible to direct photolysis by sunlight(3).

Topramezone is not expected to undergo hydrolysis(1). Topramezone does not undergo photolysis on soil or in water readily and therefore is not expected to be susceptible to direct photolysis by sunlight(1).

An estimated BCF of <1 was calculated in fish for topramezone(SRC), using an estimated log Kow of 1.44(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).

The Koc of topramezone is estimated as 140(SRC), using an estimated log Kow of 1.44(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that topramezone is expected to have high mobility in soil. However, dissipation of this compound in the environment appears to be dependent by sorption over time(4). Batch-equilibrium sorption studies indicate that topramezone may be highly mobile in some soils and sediments(4).

The Henry's Law constant for topramezone is estimated as 9.4X10-18 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that topramezone is expected to be essentially nonvolatile from water surfaces(2). Topramezone is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.8X10-12 mm Hg(SRC), determined from a fragment constant method(3).

Occupational exposure to topramezone may occur through inhalation and dermal contact with this compound at workplaces where topramezone is produced or used. (SRC)

Metabolism and pharmacokinetics. Absorption of 14C-topramezone following a single oral dose was rapid but limited, with the highest plasma concentrations observed at 1 hour (first time point measured). Oral absorption is estimated to be approximately 20% of the administered dose. The majority of the dose was recovered within 48 hours in the feces (73- 91% dose) and urine (8-29% dose) /From table/[USEPA; 40 CFR Part 180|Dermal penetration. The majority of the applied dose for each group was not absorbed (91.0-98.3% dose), with the greatest amount of the non-absorbed material being recovered from the skin wash (90.8-96.0% dose). Absorbed radioactivity was low and accounted for 0.16-2.60% of the dose for all groups for all exposures /From table/[USEPA; 40 CFR Part 180

Topramezone has herbicidal activity against broadleaf weeds and grasses. It's efficacy is the result of the inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase (HPPD) enzyme in target plants. Following treatment in sensitive plants carotenoid pigment formation, membrane structure and photosynthesis is disrupted.

INHALATION: Remove victim to fresh air. If breathing has ceased, clear the victim's airway and start mouth-to-mouth artificial respiration. If breathing is difficult, give oxygen. Contact a physician immediately. Be sure the contact areas are clean to prevent contamination of the rescuer. INGESTION: Immediately dilute the swallowed product by giving large quantities of water, but do not induce vomiting. If vomiting occurs, give fluids again. ... Never give anything by mouth to an unconscious person. Contact a physician immediately. NOTE TO PHYSICIANS: Treat according to the symptoms observed (decontamination, vital functions). There is no know specific antidote for the components in this product. /Impact/

(3-(4,5-dihydro-isoxazol-3-yl)-4-methanesulfonyl-2-methylphenyl)(5-hydroxy-1-methyl-1H-pyrazol-4-yl)methanone

IMPACT Herbicide; Topramezone SC Herbicide; topramezone 29.7%, inert ingredients 70.3%|TOPRAMEZONE SC HERBICIDE: Active Ingredient 29.7% methanone, [3-(4,5-dihydro-3-isoxazolyl)-2-methyl-4-(methylsulf onyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)-|TOPRAMEZONE TECHNICAL: Active Ingredient 99.2% methanone, [3-(4,5-dihydro-3-isoxazolyl)-2-methyl-4-(methylsulf onyl)phenyl](5-hydroxy-1-methyl-1H-pyrazol-4-yl)-

Analyte: topramezone; matrix: chemical identification; procedure: reversed-phase high-performance liquid chromatography with ultraviolet detection[Health Canada; Regulatory Note: Topramezone (REG2006-09); Pest Management Regulatory Agency (2006)|Analyte: topramezone; matrix: formulated product; procedure: isocratic high-performance liquid chromatography[Health Canada; Regulatory Note: Topramezone (REG2006-09); Pest Management Regulatory Agency (2006)|Analyte: topramezone; matrix: soil, sediment; procedure: high-performance liquid chromatography with dual mass spectrometry; quantitation limit: 0.001 ppm[Health Canada; Regulatory Note: Topramezone (REG2006-09); Pest Management Regulatory Agency (2006)|Analyte: topramezone; matrix: water; procedure: high-performance liquid chromatography; quantitation limit: 0.06 ppm[Health Canada; Regulatory Note: Topramezone (REG2006-09); Pest Management Regulatory Agency (2006)|For more Analytic Laboratory Methods (Complete) data for TOPRAMEZONE (6 total), please visit the HSDB record page.

Agrochemicals -> Herbicides|Herbicides