Norflurazon

Pesticide -> EPA IRIS

Herbicides

Active substance -> EU Pesticides database: Not approved

Pesticides -> Herbicides, Other

Pesticide (Norflurazon) -> USDA PDB

Pesticide

log Kow = 2.30

2.52

White to greyish brown, crystalline powder

Crystals from alcohol

Sparingly soluble in hydrocarbons.

Solubility at 25 °C: acetone 50 g/L; ethanol 142 g/L; xylene 2.5 g/L

In water, 33.7 mg/L at 25 °C

0.00000003 [mmHg]

2.89X10-8 mm Hg at 25 °C

Norflurazon appears as colorless odorless crystals. Non corrosive. Used as an herbicide.

White to greyish-brown odorless solid; [HSDB] Colorless odorless solid; [CAMEO] Crystalline solid; [MSDSonline]

Stable in aqueous solution @ pH 3-9 (<8% loss within 24 hr). ... Stable upon storage (shelf life (@ 20 °C) greater than or equal to 4 yr). ... Rapidly degraded by sunlight.

Stable under alkaline and acid conditions ... but susceptible to light.

This chemical does not meet GHS hazard criteria for 1.4% (1 of 70) of reports.

Warning

H400 (98.6%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

P273, P391, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 70 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Norflurazon is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

2002/2076

Norflurazon: Does not have an individual approval but may be used under an appropriate group standard

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]

Tolerances are established for the combined residues of the herbicide norflurazon (4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-tolyl)-3-(2H)-pyridazinone) and its desmethyl metabolite 4-chloro-5-(amino)-2-alpha, alpha, alpha-trifluoro-m-tolyl)-3(2H)-pyridazinone in or on the following raw agricultural commodities: [Table#6346]

The Agency has previously identified and required the submission of the generic (i.e., active ingredient specific) data required to support reregistration of products containing norflurazon as an active ingredient. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing norflurazon pending acceptance of the risk mitigation measures described in this document.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Norflurazon is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0229; Pesticide type: Herbicide; Registration Standard Date: 12/21/84; Case Status: RED Approved 06/96; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Norflurazon; Data Call-in (DCI) Date(s): 08/06/90, 01/13/93, 06/16/93, 10/13/95, 08/15/96; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

Do not contaminate water, food, or feed by storage or disposal. /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

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

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.

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.

Tolerances are established for the combined residues of the herbicide norflurazon (4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-tolyl)-3-(2H)-pyridazinone) and its desmethyl metabolite 4-chloro-5-(amino)-2-alpha, alpha, alpha-trifluoro-m-tolyl)-3(2H)-pyridazinone in or on the following raw agricultural commodities: [Table#6345]

Excerpt from ERG Guide 171 [Substances (Low to Moderate Hazard)]:

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.

LD50 /Colinus virginianus/ (Bobwhite quail) oral >1250 mg/kg

LD50 /Anas platyrhynchos/ (Mallard duck) oral >1250 mg/kg

LD50; Species: Apis mellifera (Honey bee) topical >90.6 ug/bee

LC50; Species: Lepomis macrochirus (Bluegill, juvenile); Conditions: freshwater; static; Concentration: 16.3 ppm for 96 hr (95% confidence interval: 13.3-19.9 ppm)

For more Ecotoxicity Values (Complete) data for NORFLURAZON (6 total), please visit the HSDB record page.

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.

/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

Endocrine

4 x 10 ^-2 mg/kg-day

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).

/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.

AEROBIC: Norflurazon degrades slowly in aerobic soil, with a reported half-life of 130 days(1). The biodegradation half-life under aquatic conditions is 6-8 months(1). It has been found that biodegradation in soil is influenced by environmental conditions, with the rate increasing with increasing depth (5 cm, half-life 100 days; 80 cm, half-life 260 days), increasing with increasing pH (pH 5.25, half-life 105 days; pH 7.0, half-life 225 days), and decreasing with increasing soil organic matter (0.75% OM, half-life 210 days; 2.20% OM, half-life 75 days)(2). The soil types used in this study were a Lexington silt loam (Tennessee), a Beulah silt loam (Mississippi), and a Dothan loamy sand (Georgia)(2).

ANAEROBIC: Norflurazon has a reported biodegradation half-life of 8 months under anaerobic conditions(1).

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).

Tolerances are established for the combined residues of the herbicide norflurazon (4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-tolyl)-3-(2H)-pyridazinone) and its desmethyl metabolite 4-chloro-5-(amino)-2-alpha, alpha, alpha-trifluoro-m-tolyl)-3(2H)-pyridazinone in or on the following raw agricultural commodities: [Table#6346]

The Agency has previously identified and required the submission of the generic (i.e., active ingredient specific) data required to support reregistration of products containing norflurazon as an active ingredient. The Agency has completed its review of these generic data, and has determined that the data are sufficient to support reregistration of all products containing norflurazon pending acceptance of the risk mitigation measures described in this document.

As the federal pesticide law FIFRA directs, EPA is conducting a comprehensive review of older pesticides to consider their health and environmental effects and make decisions about their future use. Under this pesticide reregistration program, EPA examines health and safety data for pesticide active ingredients initially registered before November 1, 1984, and determines whether they are eligible for reregistration. In addition, all pesticides must meet the new safety standard of the Food Quality Protection Act of 1996. Norflurazon is found on List A, which contains most food use pesticides and consists of the 194 chemical cases (or 350 individual active ingredients) for which EPA issued registration standards prior to FIFRA, as amended in 1988. Case No: 0229; Pesticide type: Herbicide; Registration Standard Date: 12/21/84; Case Status: RED Approved 06/96; OPP has made a decision that some/all uses of the pesticide are eligible for reregistration, as reflected in a Reregistration Eligibility Decision (RED) document.; Active ingredient (AI): Norflurazon; Data Call-in (DCI) Date(s): 08/06/90, 01/13/93, 06/16/93, 10/13/95, 08/15/96; AI Status: OPP has completed a Reregistration Eligibility Decision (RED) document for the case/AI.

(FL) FLORIDA 280 ug/L

(ME) MAINE 10.5 ug/L

/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.

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.

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.

Used as selective pre-emergence herbicide for control of annual grasses and broad-leaved weeds in fruits, vegetables, nuts, cotton, soy beans, other crops, and non-agricultural and industrial areas; [HSDB] Used as food additive; [Hawley]

Farming (Pesticides) [Category: Industry]

For norflurazon (USEPA/OPP Pesticide Code: 105801) ACTIVE products with label matches. /SRP: Registered for 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./

Norflurazon is a selective preemergent herbicide used to control germinating annual grasses and broadleaf weeds in fruits, vegetables, nuts, cotton, peanuts, soybeans, and various nonagricultural and industrial areas. Formulations include granular, flowable concentrate, and water dispersible granules.

For manufacturing use only in formulating herbicides /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

Norflurazon controls grasses, sedges, and rushes such as crabgrass, foxtail, goosegrass, barnyardgrass, fall panicum, signalgrass, povertygrass, rice cutgrass, needlegrass, smokegrass, spikerush, annual bluegrass, fescues, ripgut grass, ryegrass, wild barley, witchgrass, and many broadleaf weeds, such as prickly sida, common purslane, ragweed, spurred anoda, carpetweed, Florida purslane, cheeseweed, chickweed, false dandelion, fiddleneck, filaree, horseweed, London rocket, pineappleweed, puncture vine, redmaids, Russian thistle, and Shepherdspurse. ... Suppression or control ... for nutsedges, bermudagrass, quackgrass, groundsel, annual morning-glory, cocklebur, common lambsquarters, sowthistle, and pigweed. Norflurazon has practical crop tolerance for cotton, cranberries, citrus, apricots, cherries, filberts, nectarines, peaches, plums, prunes, and walnuts.

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.