Norflurazon

303.67

303.67

248-397-1

KES1HB07E4

3077

DTXSID8024234

White to greyish brown, crystalline powder|Crystals from alcohol

44.7

2.30

White Crystalline Solid

1.5±0.1 g/cm3

117 °C

345.2±52.0 °C at 760 mmHg

162.6±30.7 °C

1.567

In water, 33.7 mg/L at 25 deg C

0-6°C

2.89X10-8 mm Hg at 25 deg C

Oral-Rat LD50: 8000 mg/kg

Combustion produces toxic chloride, fluoride and nitrogen oxide gas

Odorless

Henry's Law constant = 3.43X10-10 atm-cu m/mol at 25 °C (est)

No dissociation in range of pH 1 to 12 (25 °C)

MP: 177 °C. VP: 2X10-9 torr at 20 °C|Hydroxyl radical reaction rate constant = 9.93X10-12 cu cm/molec-sec at 25 °C (est)|Ozone reaction rate constant = 1.6X10-16 cu cm/molec-sec at 25 °C (est)

No rapid reaction with air. No rapid reaction with water.

Amines, Phosphines, and Pyridines

A trifluoromethyl pyridazinone derivative.

Non-corrosive

UN30779/PG3

3

50

61

UR6150000

N

The warehouse is ventilated, low temperature and dry; stored and transported separately from food materials

Stable under alkaline and acid conditions but susceptible to light.

P273

H400

Pesticide Disposal: Wastes resulting from the use of this product may be disposed of on site or at any approved waste disposal facility. Container DIsposal: Completely empty container into application equipment. Then dispose of empty container in a sanitary landfill, or by incineration, or, if allowed by state and local authorities, by burning. If burned, stay out of smoke. /Norflurazon Technical/[EPA/OPPTS; Pesticide Product Label System (PPLS) - Search Results for Norflurazon Technical Product Label. 5 p. (August 26, 2003). Accessed from a Database Query at http://oaspub.epa.gov/pestlabl/ppls.home|Do not discharge effluent containing this product into lakes, streams, ponds, estuaries, oceans or other waters unless in accordance with the requirements of a National Pollutant Discharge Elimination System (NPDES) permit and the permitting authority has been notified in writing prior to discharge. Do not discharge effluent containing this product to sewer systems without previously notifying the local sewage treatment plant authority... /Norflurazon Technical/[EPA/OPPTS; Pesticide Product Label System (PPLS) - Search Results for Norflurazon Technical Product Label. 5 p. (August 26, 2003). Accessed from a Database Query at http://oaspub.epa.gov/pestlabl/ppls.home|Do not contaminate water when disposing of equipment washwaters. Do not apply directly to water, or to areas where surface water is present or to intertidal areas below the mean high water mark. Do not allow this material to drift onto neighboring crops or noncrop areas or use in a manner or at a time other than in accordance with label directions ...|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.

EPA/OPPTS; R.E.D. Facts for Norflurazone. EPA-738-F-96-012, 14 p. (July 1996). Available at http://www.epa.gov/REDs/factsheet/0229fact.pdf as of February 28, 2007|USEPA/Office of Pesticide Programs; Reregistration Eligibility Decision Document - Norflurazon, 201 p. (1996). The RED summarizes the risk assessment conclusions and outlines any risk reduction measures necessary for the pesticide to continue to be registered in the U.S.[Available from, as of February 28, 2007: http://www.epa.gov/pesticides/reregistration/status.htm]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Some may burn but none ignite readily. Containers may explode when heated. Some may be transported hot. For UN3508, be aware of possible short circuiting as this product is transported in a charged state. (ERG, 2016)

|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 197 companies from 3 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: SMALL FIRE: Dry chemical, CO2, water spray or regular foam. LARGE FIRE: Water spray, fog or regular foam. Do not scatter spilled material with high-pressure water streams. Move containers from fire area if you can do it without risk. Dike fire-control water for later disposal. FIRE INVOLVING TANKS: Cool containers with flooding quantities of water until well after fire is out. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. SPILL: Increase, in the downwind direction, as necessary, the isolation distance shown above. FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent dust cloud. Avoid inhalation of asbestos dust. SMALL DRY SPILL: With clean shovel, place material into clean, dry container and cover loosely; move containers from spill area. SMALL SPILL: Pick up with sand or other non-combustible absorbent material and place into containers for later disposal. LARGE SPILL: Dike far ahead of liquid spill for later disposal. Cover powder spill with plastic sheet or tarp to minimize spreading. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. (ERG, 2016)|The personal protective equipment (PPE) for handlers is to be based on the acute toxicity of the end-use product. The minimum PPE requirements for handlers include long-sleeved shirt and long pants, shoes plus socks, and chemical-resistant gloves.|When handlers use closed systems, enclosed cabs, or aircraft in a manner that meets the requirements listed in the Worker Protection Standard (WPS) for agricultural pesticides (40 CFR 170.240(d)(4-6)), the handler PPE requirements may be reduced or modified as specified in the WPS.|Agricultural Use Requirements. Use this product only in accordance with its labeling and with the Worker Protection Standard (WPS), 40 CFR part 170. ... Do not enter or allow worker entry into treated areas during the restricted-entry interval (REI) of 12 hours. PPE required for early entry to treated areas that is permitted under the WPS and that involves contact with anything that has been treated, such as plants, soil, or water, is: coveralls, waterproof gloves, and shoes plus socks. /Zorial Rapid 80/[EPA/OPPTS; Pesticide Product Label System (PPLS) - Search Results for Zorial Rapid 80 Product Label. 29 p. (October 24, 2003). Accessed from a Database Query at http://oaspub.epa.gov/pestlabl/ppls.home|Products Intended Primarily for Occupational Use ... Early Entry PPE: The PPE for early entry are the minimum that would be required under the Worker Protection Standard. These are: coveralls, chemicalresistant gloves, and shoes plus socks.

Nonflammable

For minor spills, leaks, etc., follow all precautions indicated on the label and clean up immediately. Take special care to avoid contamination of equipment and facilities during cleanup procedures and disposal of wastes... /Norflurazon Technical/[EPA/OPPTS; Pesticide Product Label System (PPLS) - Search Results for Norflurazon Technical Product Label. 5 p. (August 26, 2003). Accessed from a Database Query at http://oaspub.epa.gov/pestlabl/ppls.home

If inhaled, move person to fresh air. If person is not breathing, call 911 or an ambulance, then give artificial respiration ... Call a poison control center or doctor for further trearnent advice. If swallowed, call a poison control center or doctor for further treatment advice. Have person sip a glass of water if able to swallow. Do not induce vomiting unless told to do so by the poison control center or doctor. Do not give anything by mouth to an unconscious person. /Norflurazon Technical/[EPA/OPPTS; Pesticide Product Label System (PPLS) - Search Results for Norflurazon Technical Product Label. 5 p. (August 26, 2003). Accessed from a Database Query at http://oaspub.epa.gov/pestlabl/ppls.home|Entry Restrictions - Products Intended Primarily for Occupational Use ... an increase in the Restricted Entry Interval (REI) above what is required in the Worker Protection Standard (WPS) is /not/ warranted. The current 12-hour REI, pertaining to each use of the product that is within the scope of the WPS, is to be maintained. The 12-hour REI is the minimum REI for norflurazon. Early Entry PPE: The PPE for early entry are the minimum that would be required under the WPS. These are: coveralls, chemicalresistant gloves, and shoes plus socks.|Entry Restrictions - Products Intended Primarily for Occupational Use (NonWPS Uses) Some registered uses of norflurazon are outside of the scope of the Worker Protection Standard (WPS). For non-WPS uses, the /EPA/ is requiring the following: For liquid applications: "Do not enter or allow others to enter the treated area until sprays have dried." For granular applications: "Do not enter or allow others to enter the treated area until dusts have settled. In addition, if the granules are watered-in, do not enter or allow others to enter until the treated area is dry, following the watering-in.|Products Intended Primarily for Occupational Use. The /EPA/ is requiring the following labeling statements to be located on all end-use products containing norflurazon that are intended primarily for occupational use. Application restrictions: Do not apply this product in a way that will contact workers or other persons, either directly or through drift. Only protected handlers may be in the area during application.|For more Preventive Measures (Complete) data for NORFLURAZON (9 total), please visit the HSDB record page.

SEDIMENT: Norflurazon was not detected in sediment samples from a survey of south Florida canals conducted from November 1991 to June 1995 (detection limit 10 ug/kg)(1).

Norflurazon runoff following 3.8 cm of rainfall applied at 24 hours after application of both norflurazon and fluometuron as 0.4 kg active ingredient/ha from non-crop runoff trays with Bosket sandy loam soil at 1.1% slope was 6.0 mg/L of first liter of runoff, 4.4% of applied compounds(1). No loss was noted from crop-residue trays(1).

practically nontoxic

LD50 Rabbit percutaneous >20,000 mg/kg|LD50 Rat percutaneous >5000 mg/kg|LD50 Rat oral >8000 mg/kg

/BIRDS and MAMMALS/ Norflurazon is practically nontoxic to ... /adult birds/ on an acute oral and subacute dietary basis ... Causes reproductive effects in birds. Norflurazon is also practically nontoxic to /adult/ mammals...|/AQUATIC SPECIES/ ... Due to its mobility and long half-life it presents a potential for groundwater contamination. The aim of /the/ study was to investigate toxic effects of norflurazon on non-targeted aquatic bioindicator organism, the planarian Polycelis felina (Daly.). Animals were exposed to water solutions of norflurazon in concentrations 200, 20, 2 and 0.2 uM. ... The results showed that norflurazon caused mortality, locomotive, morphological and histological changes in treated animals compared to corresponding controls. The most prominent histological changes were damage of the outer mucous layer, lack of rhabdites, damage to epidermis and extensive damage to parenchyma cells. The results of alkaline comet assay indicated that norflurazon in concentrations of 2 and 0.2 uM induces significant increase of primary DNA damage in planarian cells compared to the corresponding control animals. The mean values of all three measured parameters were significantly elevated on the fourth day of the treatment compared with the first and the seventh day.|/AQUATIC SPECIES/ In acute oral toxicity studies, norflurazon is moderately to slightly toxic to both cold and warm water fish. In a fish early life stage study, norflurazon caused chronic effects to fish at levels as low as 1.5 ppm. In an aquatic invertebrate study, norflurazon was slightly toxic. It may cause chronic effects on aquatic invertebrate survival and offspring production. Norflurazon is slightly to moderately toxic to estuarine/marine organisms.|/OTHER TERRESTRIAL SPECIES/ Norflurazon is also practically nontoxic to ... insects (honeybees). (a.i. 97.6 & 80%, LD50 > 235 & > 90 ug a.i. per bee,respectively|For more Ecotoxicity Excerpts (Complete) data for NORFLURAZON (6 total), please visit the HSDB record page.

Norflurazon's production may result in its release to the environment through various waste streams; it's use as a herbicide(1) will result in its direct release to the environment(SRC).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 420(SRC), determined from a log Kow of 2.30(2) and a regression-derived equation(3), indicates that norflurazon is expected to have moderate mobility in soil(SRC). It is suggested that the adsorption mechanism may be due primarily to hydrophobic association of the organic molecule with the soil organic matter surface(4). Volatilization of norflurazon from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 3.43X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 2.89X10-8 mm Hg(5), and water solubility, 33.7 mg/L(5). Norflurazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(5). A reported soil biodegradation half-life of 130 days(6) indicates that biodegradation is not an important environmental fate process in soil(SRC).|TERRESTRIAL FATE: In sandy loam soil, at 5, 20, and 35 °C, norflurazon dissipation was 10, 80 and 97 percent of total applied (not specified) after 210 days and was converted to its monomethyl and demethylated metabolites. At 20 and 35 °C, the compound exhibited a half-life of 50 and 9 days, respectively. The half-life of norflurazon in soil was about 8 months and the demethylated metabolite of norflurazon was observed(1).|TERRESTRIAL FATE: In a field study using plots of Lexington silt loam (Tennessee), Beulah silt loam (Mississippi), and Dothan loamy sand (Georgia), norflurazon exhibited half-lives ranging from 7 to 79 days in the 0-8 cm soil horizons(1). Dry field conditions slowed the rate of dissipation and the chemical was not detected below the 15 cm horizon. Concentrations in the 8 to 15 cm zone were <36 ppbw 112 days after treatment with 1.7 kg active ingredient/ha(1).|TERRESTRIAL FATE: The average half life of norflurazon residues in soil from the Delta and Southeast is 45 to 180 days depending on clay and organic content.|For more Environmental Fate (Complete) data for NORFLURAZON (7 total), please visit the HSDB record page.

The rate constant for the vapor-phase reaction of norflurazon with photochemically-produced hydroxyl radicals has been estimated as 9.93X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 39 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). The rate constant for the vapor-phase reaction of norflurazon with ozone has been estimated as 1.6X10-16 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 days at an atmospheric concentration of 7X10+11 ozone molecules per cu cm(2). Norflurazon is stable to hydrolysis in the environment(4) due to the lack of functional groups that hydrolyze under environmental conditions(3). Norflurazon contains chromophores that absorb at wavelengths >290 nm and therefore may be susceptible to direct photolysis by sunlight(3). The main route of dissipation is photodegradation of norflurazon in water(4). Low volatilization but significant photolytic losses occurred when norflurazon-treated soil coated slides were exposed to ultraviolet or sunlight(5). February photodegradation half-life of norflorazon in natural water taken from the Murray River in South Australia, a vineyard region, was 2.34 days, using borosilicate glass flasks and employing incident sunlight; the average temperature was 17 to 32 °C(6). No April photodegradation was observed, average temperature of 10 to 21 °C(6).

An estimated BCF of 12 was calculated in fish for norflurazon(SRC), using a log Kow of 2.30(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).

1.91e+03 L/kg|The Koc of norflurazon is estimated as 420(SRC), using a log Kow of 2.30(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that norflurazon is expected to have moderate mobility in soil. Binding does appear to be influenced by organic matter, clay content and cation exchange capacity(4). Koc values of 3,311(5) and 1,914(6) have been reported for norflurazon although it is generally observed that norflurazon is expected to be mobile to highly mobile in soil(7).|Norflurazon adsorption increases and therefore mobility decreases as soil organic matter and clay content increases(2). Of 5 ug/g soil of norflurazon applied on the surface of Myakka sand, approximately 0.30 ug/g soil was not sorbed in the top 25 cm horizon of soil and 0.02 ug/g soil of norflurazon was not adsorbed below 150 cm; therefore, it is considered as potentially leachable(1). A study using Commerce clay loam (36% sand, 31% silt, 33% clay) near Baton Rouge, LA found cumulative loss of norflurazon through leaching to be 0.68g/ha(0.03% of applied) with 1000 mm rain in 302 days, and 3.66 g/ha (0.16% of applied) with 2084 mm rain in 308 days for the 1988-89 and 1989-90 seasons, respectively, which suggested to the investigators that soil leaching of this herbicide could be an important disappearance pathway(5). It appears that out of 5 ug/g applied, 1.43 ug/g norflurazon is leachable below 120 cm depth of soil in Candler fine sand(1). Upward movement (an excess of 5 cm in 8 weeks) occurred in subirrigated columns containing herbicide-treated Herbert silt loams(2). Norflurazon leached a total of approximately 65% of applied in 5 pore volumes (equal to 15.2 cm rainfall) in Candler fine sand (97% sand, 1.1% organic matter)(3). A study using ryegrass dry matter production as a measure of herbicide movement through soil found that norflurazon had very slow movement by leaching in Astatula fine sand soil (96.5% sand, 2.0% silt, 1.5% clay, and 0.6% organic matter) which was attributed to its relatively low water solubility(4). Two studies using five different Georgia soils, found that disappearance and leaching of norflurazon was slow and that leaching did not appear to be an important method of norflurazon loss(6,7). Norflurazon does not leach appreciably(8).|Using a soil TLC study, the Rf for norflurazon was determined to be 0.40(1). Norflurazon is easily carried off applied fields by runoff or percolation(2). Using soils representative of the southern citrus-belt of Florida (La Belle, Hendry Co.), Kd values ranging from 0.63 to 2.20 mL/g were obtained, indicating weak to moderate binding; the Kd was significantly related to organic C content, soil pH, and cation exchange capacity(3). Kd values of 1.21, 1.49, 0.63, 1.34, 1.55, 2.20, and 1.94 mL/g were measured using Riveria (fine sand, pH 6.2, 0.94% OC, 5.1% clay, 4.11 cmol/kg CEC), Wabasso (sand, pH 6.62, 0.61% OC, 2.4% clay, 2.54 cmol/kg CEC), Holopaw (fine sand, pH 6.10, 0.50% OC, 1.3% clay, 2.03 cmol/kg CEC), Basinger (fine sand, pH 5.75, 0.61% OC, 1.9% clay, 1.52 cmol/kg CEC), Pineda (fine sand, pH 7.11, 1.22% OC, 0.5% clay, 8.40 cmol/kg CEC), Chobee (fine sandy loam, pH 7,18, 1.39% OC, 16.1% clay, 8.10 cmol/kg CEC), and Boca (fine sand, pH 7.05, 1.67% OC, 3.5% clay, 10.79 cmol/kg CEC), respectively(3). Using Commerce clay loam field plots, Baton Rouge, LA (36% sand, 31% silt, 33% clay) norflurazon concentrations in the top 15 cm of soil following 2.24 kg/ha application on 6.1.88 were (day, concn in ng/g): 1, 372; 20, 224; 44, 167; 106, 160; 169, 29; 293, 39; results following application on 4/26/89 were (day, concn in ng/g): 5, 404; 34, 301; 76, 30; 134, 187; 224, 150; 352, 119(4). Leaching studies using the South Australian Barossa Valley viticultural region soils which are generally low in organic carbon content indicate that norflurazon does leach more readily in sandy soils than clayey soils(5).|The trifluoromethyl group may enhance the mobility of norflurazon(1). Norflurazon adsorption increases, thereby decreasing mobility with increasing soil organic matter and clay content(2). Sorption of norflurazon on Candler fine sand increases with increasing ionic strength of electrolyte(3). Sorption of norflurazon also varies with the cation species in the electrolyte in the following order: Fe >> Al = Cu > K = Ca = Mg = Na(3). The adsorption isotherm of norflurazon appears to be curvilinear(4). It is suggested that the adsorption mechanism may be due primarily to hydrophobic association of the organic molecule with the soil organic matter surface(4). The sorption coefficient (0.63-2.2 mL/g in Citrus soils indicating weak to moderate binding to soil) is strongly related to organic C content, soil pH, and cation exchange capacity(5). The half-lives estimated for norflurazon in soil are 30 and 90 days(6,7).

The Henry's Law constant for norflurazon is estimated as 3.4X10-10 atm-cu m/mole(SRC) derived from its vapor pressure, 2.89X10-8 mm Hg(1), and water solubility, 33.7 mg/L(1). This Henry's Law constant indicates that norflurazon is expected to be essentially nonvolatile from water surfaces(2). Norflurazon is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

GROUNDWATER: Norflurazon was not detected in groundwater samples analyzed as part of a comprehensive survey of literature addressing pesticide use on golf courses conducted in 1996(1).|DRINKING WATER: A study of 783 rural domestic wells and 566 community water system wells (detection limit = 0.18 ug/L)(1), and another study of 68,824 wells in 45 states (detection limit not reported), did not detect norflurazon in any samples(2).|SURFACE WATER: In a study of the Mississippi River, norflurazon was detected in the Yazoo River (Mississippi) going into the Mississippi at concentrations of 0.3 ug/L, 0.15 ug/L and 0.32 ug/L for Jul-Aug, 1991, Oct-Nov, 1991, and Mar-Apr, 1992, respectively; in the Mississippi River below Vicksburg, MS - 0.2 ug/L, 0.3 ug/L and not detected for Jul-Aug, 1991, Oct-Nov, 1991, and Mar-Apr, 1992, respectively; 0.3 ug/L, 0.3 ug/L and 0.2 ug/L near St. Francisville, LA for Jul-Aug, 1991, Oct-Nov, 1991, and Mar-Apr, 1992, respectively; below Belle Chasse, LA 0.3 ug/L, 0.4 ug/L and not detected for Jul-Aug, 1991, Oct-Nov, 1991, and Mar-Apr, 1992, respectively(1). It is estimated that the annual mass transport of norflurazon in the dissolved phase from the Mississippi River into the Gulf of Mexico is 10 metric tons based on two sampling trips(1). Norflurazon concentrations in three streams in the Mississippi River Delta in a region of rice and cotton operations were as follows: not detected to 35 ng/L, 2.5-28 ng/L and not detected to 58 ng/L in samples from the Steele Bayou near Rolling Fork, Deer Creek near Hollandale and the Big Sunflower River near Anguilla, respectively(2). Samples were analyzed during 1995 with highest norflurazon concentrations occurring early in the growing season (April and May) and then decreasing later in the season(2). Data was collected on the San Joachim River Valley during January through December 1993 with pesticides being detected in all but one of the 143 surface-water samples collected from the San Joachim River, Orestimba Creek, Salt Slough, and the Merced River(3). Norflurazon (detection limit 0.024 ug/L) was detected in 1.3% of 76 samples with a maximum concentration of 0.44 ug/L(3). In a survey of south Florida canals conducted from November 1991 to June 1995, norflurazon was one of the most frequently detected pesticides, being identified in 54 samples with a maximum concentration of 3.9 ug/L (detection limit 0.2-0.3 ug/L)(4). Norflurazon was detected in the Rhine River at Basel at a concentration of 0.2 ug/L, the result of a spill in 1988-1989(5).

Occupational exposure to norflurazon may occur through inhalation. Monitoring data indicate that the general population may be exposed to norflurazon via dermal contact with contaminated surface water. (SRC)

Pesticides used to destroy unwanted vegetation, especially various types of weeds, grasses (POACEAE), and woody plants. Some plants develop HERBICIDE RESISTANCE. (See all compounds classified as Herbicides.)

Both compounds /SAN-6706 and norflurazon/ were readily absorbed from nutrient solution by cotton (Gossypium hirsutum Leguminatae "Coker 203"), corn (Zea mays Leguminatae "WF9") and soybean (Glycine max (Leguminatae) Merr. "Lee") plants. In corn and soybean plants, these compounds were translocated more rapidly and in greater amount than in cotton.|Female Sprague-Dawley-rats were administered single doses of 0, 2, or 110 mg/kg carbon-14 (C-14)-labeled norflurazon by gavage. Some of the rats given 2 mg/kg radiolabeled norflurazon had been maintained on a diet containing 2 mg/kg unlabeled norflurazon for 14 days previously. Other rats were administered 0 or 2 mg/kg C-14 labeled norflurazon intravenously (iv). Urine, feces, and expired air were collected for 4 days and analyzed for C-14 activity. ... The rats were killed after 4 days to determine the tissue distribution of C-14 activity. Cumulative urinary excretion of C-14 label ranged from 18.5 to 28.4% of the doses. The largest excretion was by rats dosed iv and the smallest by rats given the single 110 mg/kg dose. Cumulative fecal excretion of C-14 activity ranged from 65.3 to 79.5%. Rats given the 110 mg/kg dose excreted the most radiolabel and those given 2 mg/kg after 14 days of dietary treatment the least. Only 0.1% of the doses was eliminated in the expired air. Less than 1% of each dose was recovered in the tissues and carcass. Only the liver and kidney contained relatively high levels of C-14 activity...|(14)C 4-Chloro-5-dimethylamino-2(a,a,a-trifluroo-m-tolyl)-3(2H)-pyridazinone was added to solutions in Ehrlenmeyer flasks in which cranberry cuttings were propagated. Subsequently, leaf, shoot and root were analyzed. Within one day, norflurazon and an unidentified metabolite were detected in the roots. After 15 days, in addition to norflurazon, 4-chloro-5-amino-2-(a,a,a,-trifluoro-m- tolyl)-3(2H)-pyridazinone was identified in leaf shoot and root. When norflurazon was applied to the plants, 4-chloro-5-amino-2-(a,a,a,-trifluoro-m- tolyl)-3(2H)-pyridazinone and an unidentified metabolite were observed in leaf, stem and root after 8 days.

Norflurazon was administered as single oral doses of 2 or 110 mg/kg, a single i.v. dose of 2 mg/kg, or a single oral dose of 2 mg/kg following administration of 2 ppm in animal diet for 14 days to separate groups of rats. In urine, between 18.5-28.4% of the administered dose was eliminated by 96 hours post-dose, and between 65.3-79.5% of the administered dose was eliminated in feces. Thirteen metabolites of norflurazon were isolated. There appear to be 4 pathways for norflurazon metabolism: N-demethylation; displacement of the chlorine atom by glutathione; glutathione attack on the aromatic ring; and replacement of the chlorine atom by hydrogen ... . An additional metabolism study was conducted to determine the presence of the sulfone metabolite in rat excreta after a single low oral dose of 1 mg/kg, or a single high oral dose of 100 mg/kg. The sulfone metabolite was detected in both urine and feces of dosed rats. In urine, the sulfone metabolite accounted for 0.03% of urinary radioactivity at the low dose, and 0.2% of urinary radioactivity at the high dose. The sulfone metabolite accounted for 0.3% of fecal radioactivity at the low dose, and for 0.1% of fecal radioactivity at the high dose.|4-Chloro-5-dimethylamino-2-(a,a,a-trifluoro-m- tolyl)-3(2H)-pyridazinone was not degraded to any great extent in cotton. In corn and soybean, significant amounts of the mono- and des-methyl derivatives were seen after 24 hr. Metabolism of norflurazone also was more rapidly in corn and soybean than in cotton.|(14)C 4-Chloro-5-dimethylamino-2(a,a,a-trifluroo-m-tolyl)-3(2H)-pyridazinone was added to solutions in Ehrlenmeyer flasks in which cranberry cuttings were propagated. Subsequently, leaf, shoot and root were analyzed. Within one day, norflurazon and an unidentified metabolite were detected in the roots. After 15 days, in addition to norflurazon, 4-chloro-5-amino-2-(a,a,a,-trifluoro-m- tolyl)-3(2H)-pyridazinone was identified in leaf shoot and root. When norflurazon was applied to the plants, 4-chloro-5-amino-2-(a,a,a,-trifluoro-m- tolyl)-3(2H)-pyridazinone and an unidentified metabolite were observed in leaf, stem and root after 8 days.|The metabolism of norflurazon was investigated in ... female Sprague-Dawley-rats administered single doses of 0, 2, or 110mg/kg carbon-14 (C-14) labeled norflurazon by gavage. Some of the rats given 2mg/kg radiolabeled norflurazon had been maintained on a diet containing 2 mg/kg unlabeled norflurazon for 14 days previously. Other rats were administered 0 or 2 mg/kg C-14 labeled norflurazon intravenously (iv).Urine, feces, and expired air were collected for 4 days and analyzed ... for norflurazon metabolites. ... Six urinary metabolites were detected. Except for rats given the 110mg/kg dose, norflurazon-sulfoxide (NFS) was identified as the most abundant metabolite, accounting for 24 to 39% of the doses. The most abundant metabolite excreted by 110mg/kg rats was not identified. Ten fecal metabolites were detected, with NFS again identified as the predominant metabolite. Less than 2% of each dose was excreted as unchanged norflurazon. The authors conclude that norflurazon when given orally to rats is metabolized extensively primarily by N-demethylation and conjugation with glutathione.|For more Metabolism/Metabolites (Complete) data for NORFLURAZON (6 total), please visit the HSDB record page.

/The authors/cloned and sequenced a gene, pds, from the cyanobacterium Synechococcus PCC7942 that is responsible for resistance to the bleaching herbicide norflurazon. A point mutation in that gene, leading to an amino acid substitution from valine to glycine in its polypeptide product, was found to confer this resistance. Previous studies with herbicide-resistant mutants have indicated that this gene encodes phytoene desaturase (PDS), a key enzyme in the biosynthesis of carotenoids. A short amino acid sequence that is homologous to conserved motifs in the binding sites for NAD(H) and NADP(H) was identified in PDS, suggesting the involvement of these dinucleotides as cofactors in phytoene desturation.|Acts as a plant pigment inhibitor /in target species/. ... Inhibits biosynthesis of carotenoids. Without carotenoid pigments to filter the light, photodegradation occurs, hence chlorosis in nontolerant plants.

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Inhalation of material may be harmful. Contact may cause burns to skin and eyes. Inhalation of Asbestos dust may have a damaging effect on the lungs. Fire may produce irritating, corrosive and/or toxic gases. Some liquids produce vapors that may cause dizziness or suffocation. Runoff from fire control may cause pollution. (ERG, 2016)

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]: Ensure that medical personnel are aware of the material(s) involved and take precautions to protect themselves. Move victim to fresh air. Call 911 or emergency medical service. Give artificial respiration if victim is not breathing. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush skin or eyes with running water for at least 20 minutes. (ERG, 2016)

/CASE REPORTS/ This report concerned a 53 year old professional weed sprayer who was referred for patch testing. He had an acute episode that resembled sunburn and caused his eyes to almost completely close, followed several days later by urticaria like lesions. He had been using the Predict formulation of norflurazon around that time. Patch testing with Predict at 1.0% and 0.1% produced a ++ reaction at 2 and 4 days after dosing. Tests in 20 control subjects were negative. The concentration of norflurazon in the preparation was 78.6%, but information on inert ingredients was not available.

4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-tolyl)-3(2H)-pyridazinone

NORFLURAZON TECHNICAL Active Ingredient 97.4% Norflurazon|ZORIAL RAPID 80 HERBICIDE Active Ingredient 78.6% Norflurazon|SOLICAM DF HERBICIDE Active Ingredient 78.6% Norflurazon|RIVERDALE PREDICT HERBICIDE Active Ingredient 78.6% Norflurazon|For more Formulations/Preparations (Complete) data for NORFLURAZON (6 total), please visit the HSDB record page.

Norflurazon is a bleaching, preemergence herbicide.|The WHO Recommended Classification of Pesticides by Hazard identifies Norflurazon (technical grade) as unlikely to present an acute hazard in normal use; Main Use: herbicide.|Norflurazon is applied using aerial application, chemigation (drip and/or sprinkler), and soil treatment (broadcast and incorporation). Use practice limitations prohibit applying norflurazon through any type of irrigation system (only for the Zorial Rapid 80 product); grazing livestock in treated areas or cut treated crops for feed; grazing or harvesting for forage or hay; and grazing or feeding for forage. Norflurazon was first registered as a pesticide in the U.S. in 1974.|All products containing norflurazon are intended primarily for occupational use. At this time no products containing norflurazon are intended for homeowner use. None of the registered occupational uses are likely to involve applications at residential sites.|For more General Manufacturing Information (Complete) data for NORFLURAZON (7 total), please visit the HSDB record page.

Product analysis is by GLC with FID, or by TLC, followed by UV spectrometry of the eluted compound; residues may be determined by GLC with ECD.|Analysis of products: By GLC with FID; analysis of residues: By GLC with ECD. In plant tissue by reverse phase HPLC. In crops, by TLC followed by GLC.|Method: EPA 1656; Procedure: gas chromatography with halogenspecific detector (electrolytic conductivity detector); Analyte: acephate; Matrix: municipal and industrial wastewater; Detection Limit: 50 ng/L.|Method: USGS-NWQL O-1131-95; Procedure: high performance liquid chromatography using ultraviolet spectrometry; Analyte: norflurazon; Matrix: filtered natural-water; Detection Limit: 0.024 ug/L.|For more Analytic Laboratory Methods (Complete) data for NORFLURAZON (8 total), please visit the HSDB record page.

Agrochemicals -> Herbicides|Pharmaceuticals