FLUORIDE ACTION NETWORK PESTICIDE PROJECT
Return to FAN's Pesticide Homepage
Return to Norflurazon Index Page
Norflurazon. TOXNET profile from Hazardous Substances Data Bank.
See for Updates: http://toxnet.nlm.nih.gov/cgi-bin/sis/search
NORFLURAZON
CASRN: 27314-13-2
For other data, click on the Table of Contents
Human Health Effects:
Probable Routes of Human Exposure:
Herbicides, such as norflurazon, can
be absorbed into the body by three routes: dermal contact, inhalation, and ingestion(1).
Emergency Medical Treatment:
Emergency Medical Treatment:
| EMT Copyright Disclaimer: |
| Portions of the POISINDEX(R) database are provided here for
general reference. THE COMPLETE POISINDEX(R) DATABASE, AVAILABLE FROM MICROMEDEX,
SHOULD BE CONSULTED FOR ASSISTANCE IN THE DIAGNOSIS OR TREATMENT OF SPECIFIC
CASES. Copyright 1974-1998 Micromedex, Inc. Denver, Colorado. All Rights
Reserved. Any duplication, replication or redistribution of all or part
of the POISINDEX(R) database is a violation of Micromedex' copyrights and
is strictly prohibited.
The following Overview, *** GENERAL OR UNKNOWN CHEMICAL ***, is relevant for this HSDB record chemical. |
| Life Support: |
o This overview assumes that basic life support measures
have been instituted.
|
| Clinical Effects: |
SUMMARY OF EXPOSURE
0.2.1.1 ACUTE EXPOSURE
o A SPECIFIC REVIEW on the clinical effects and treatment
of individuals exposed to this agent HAS NOT YET BEEN
PREPARED. The following pertains to the GENERAL
EVALUATION and TREATMENT of individuals exposed to
potentially toxic chemicals.
o GENERAL EVALUATION -
1. Exposed individuals should have a careful, thorough
medical history and physical examination performed,
looking for any abnormalities. Exposure to chemicals
with a strong odor often results in such nonspecific
symptoms as headache, dizziness, weakness, and nausea.
o IRRITATION -
1. Many chemicals cause irritation of the eyes, skin, and
respiratory tract. Respiratory tract irritation, if
severe, can progress to pulmonary edema, which may be
delayed in onset for up to 24 to 72 hours in some
cases.
2. Irritation or burns of the esophagus or
gastrointestinal tract are also possible if caustic or
irritant chemicals are ingested.
o HYPERSENSITIVITY -
1. A number of chemical agents produce an allergic
hypersensitivity dermatitis or asthma with
bronchospasm and wheezing with chronic exposure.
|
| Laboratory: |
o A number of chemicals produce abnormalities of the
hematopoietic system, liver, and kidneys. Monitoring
complete blood count, urinalysis, and liver and kidney
function tests is suggested for patients with significant
exposure.
o If respiratory tract irritation or respiratory depression
is evident, monitor arterial blood gases, chest x-ray, and
pulmonary function tests.
|
| Treatment Overview: |
SUMMARY EXPOSURE
o A specific review on the clinical effects and treatment
of individuals exposed to this agent has not yet been
prepared. The following pertains to the general
evaluation and treatment of individuals exposed to
potentially toxic chemicals.
o Move victims of inhalation exposure from the toxic
environment and administer 100% humidified supplemental
oxygen with assisted ventilation as required. Exposed
skin and eyes should be copiously flushed with water.
1. Rescuers must not enter areas with potential high
airborne concentrations of this agent without
SELF-CONTAINED BREATHING APPARATUS (SCBA) to avoid
becoming secondary victims.
o Measures to decrease absorption may be useful. The
decision to induce or not to induce emesis in ingestions
must be carefully considered. If the patient has any
signs of esophageal or gastrointestinal tract irritation
or burns, or has evidence of a decreased sensorium, a
depressed gag reflex, or impending shock, INDUCED EMESIS
SHOULD BE AVOIDED.
ORAL EXPOSURE
o GASTRIC LAVAGE
1. Significant esophageal or gastrointestinal tract
irritation or burns may occur following ingestion. The
possible benefit of early removal of some ingested
material by cautious gastric lavage must be weighed
against potential complications of bleeding or
perforation.
2. GASTRIC LAVAGE: Consider after ingestion of a
potentially life-threatening amount of poison if it can
be performed soon after ingestion (generally within 1
hour). Protect airway by placement in Trendelenburg
and left lateral decubitus position or by endotracheal
intubation. Control any seizures first.
a. CONTRAINDICATIONS: Loss of airway protective reflexes
or decreased level of consciousness in unintubated
patients; following ingestion of corrosives;
hydrocarbons (high aspiration potential); patients at
risk of hemorrhage or gastrointestinal perforation;
and trivial or non-toxic ingestion.
o ACTIVATED CHARCOAL
1. Activated charcoal binds most toxic agents and can
decrease their systemic absorption if administered soon
after ingestion. In general, metals and acids are
poorly bound and patients ingesting these materials
will not likely benefit from activated charcoal
administration.
a. Activated charcoal should not be given to patients
ingesting strong acidic or basic caustic chemicals.
Activated charcoal is also of unproven value in
patients ingesting irritant chemicals, where it may
obscure endoscopic findings when the procedure is
justified.
2. ACTIVATED CHARCOAL: Administer charcoal as slurry (240
mL water/30 g charcoal). Usual dose: 25 to 100 g in
adults/adolescents, 25 to 50 g in children (1 to 12
years), and 1 g/kg in infants less than 1 year old.
o DILUTION -
1. Immediate dilution with milk or water may be of benefit
in caustic or irritant chemical ingestions.
2. DILUTION: Following ingestion and/or prior to gastric
evacuation, immediately dilute with 4 to 8 ounces (120
to 240 mL) of milk or water (not to exceed 15 mL/kg in
a child).
o IRRITATION -
1. Observe patients with ingestion carefully for the
possible development of esophageal or gastrointestinal
tract irritation or burns. If signs or symptoms of
esophageal irritation or burns are present, consider
endoscopy to determine the extent of injury.
o OBSERVATION CRITERIA -
1. Carefully observe patients with ingestion exposure for
the development of any systemic signs or symptoms and
administer symptomatic treatment as necessary.
2. Patients symptomatic following exposure should be
observed in a controlled setting until all signs and
symptoms have fully resolved.
INHALATION EXPOSURE
o DECONTAMINATION -
1. INHALATION: Move patient to fresh air. Monitor for
respiratory distress. If cough or difficulty breathing
develops, evaluate for respiratory tract irritation,
bronchitis, or pneumonitis. Administer oxygen and
assist ventilation as required. Treat bronchospasm
with beta2 agonist and corticosteroid aerosols.
o IRRITATION -
1. Respiratory tract irritation, if severe, can progress
to pulmonary edema which may be delayed in onset up to
24 to 72 hours after exposure in some cases.
o PULMONARY EDEMA/NON-CARDIOGENIC -
1. PULMONARY EDEMA (NONCARDIOGENIC): Maintain ventilation
and oxygenation and evaluate with frequent arterial
blood gas or pulse oximetry monitoring. Early use of
PEEP and mechanical ventilation may be needed.
o BRONCHOSPASM -
1. If bronchospasm and wheezing occur, consider treatment
with inhaled sympathomimetic agents.
o OBSERVATION CRITERIA -
1. Carefully observe patients with inhalation exposure for
the development of any systemic signs or symptoms and
administer symptomatic treatment as necessary.
2. Patients symptomatic following exposure should be
observed in a controlled setting until all signs and
symptoms have fully resolved.
EYE EXPOSURE
o DECONTAMINATION: Irrigate exposed eyes with copious
amounts of tepid water for at least 15 minutes. If
irritation, pain, swelling, lacrimation, or photophobia
persist, the patient should be seen in a health care
facility.
DERMAL EXPOSURE
o DERMAL DECONTAMINATION -
1. DECONTAMINATION: Remove contaminated clothing and wash
exposed area thoroughly with soap and water. A
physician may need to examine the area if irritation
or pain persists.
o PESTICIDES -
1. DECONTAMINATION: Remove contaminated clothing and
jewelry. Wash the skin, including hair and nails,
vigorously; do repeated soap washings. Discard
contaminated clothing.
o IRRITATION -
1. Treat dermal irritation or burns with standard topical
therapy. Patients developing dermal hypersensitivity
reactions may require treatment with systemic or
topical corticosteroids or antihistamines.
o DERMAL ABSORPTION -
1. Some chemicals can produce systemic poisoning by
absorption through intact skin. Carefully observe
patients with dermal exposure for the development of
any systemic signs or symptoms and administer
symptomatic treatment as necessary.
|
| Range of Toxicity: |
o No specific range of toxicity can be established for the
broad field of chemicals in general.
|
Animal Toxicity Studies:
Non-Human Toxicity Excerpts:
Monodemethylated norflurazone is more phytotoxic than 4-chloro-5-dimethylamino-
2-(a,a,a-trifluoro-m-tolyl)-3(2H)-pyridazinone.
In 2 yr feeding trials, no effect level for rats was 375 mg/kg/day. No teratogenic
or mutagenic activity and no adverse effects on reproduction.
Non-Human Toxicity Values:
LD50 Rabbit percutaneous >20,000 mg/kg
LD50 Rat percutaneous >5000 mg/kg
LD50 Rat oral >8000 mg/kg
Ecotoxicity Values:
LD50 Bobwhite quail oral >1250 mg/kg
LD50 Mallard duck oral >1250 mg/kg
Metabolism/Pharmacokinetics:
Metabolism/Metabolites:
4-Chloro-5-dimethylamino-2-(a,a,a-trifluoro-m- tolyl)-3(2H)-pyridazinone was
not degraded to any great extent in cotton. In 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.
When applied to soybeans, 4-chloro-5-dimethylamino-2-(a,a,a-trifluoro-m-tolyl)-
3(2H)-pyridazinone was converted to the desmethyl analog. In soybeans and sicklepod
(Casia obtusifolia Leguminate), the primary metabolic pathway was N-demethylation
to norflurazon and desmethyl 4-chloro-5-amino-2-(a,a,a-tri-fluoro-m-tolyl)-3(2H)-pyridazinone.
Another pathway present in the plant roots produced polar compounds. Corn also
demethylated analog norflurazon.
Absorption, Distribution & Excretion:
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.
(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.
Mechanism of Action:
Acts as a plant pigment inhibitor. ... Inhibits biosynthesis of carotenoids.
Without carotenoid pigments to filter the light, photodegradation occurs, hence
chlorosis in nontolerant plants.
Pharmacology:
Environmental Fate & Exposure:
Environmental Fate/Exposure Summary:
Norflurazon's use as an herbicide
will result in its release to the environment through various herbicidal applications.
It has been detected in the waters of the Mississippi and its tributaries. If
released to soil, norflurazon mobility
is expected to be low to immobile. Microbial breakdown of norflurazon
appears to be responsible for the disappearance from the soil environment (reported
half-lives of 30 to 92 days). Volatilization and photodegradation are also shown
to be factors responsible for disappearance of norflurazon
when exposed on the soil surface. If released to water, norflurazon
will be essentially non-volatile. Biodegradation in water may occur based upon
reported half-lives in soil of 30-90 days. Bioconcentration is not expected
to be an important fate process; however, adsorption to sediment may be possible
based on high Koc values. If released to the atmosphere, norflurazon
will exist in the vapor and particulate phases. In the vapor phase, it will
degrade in the atmosphere by reaction with photochemically produced hydroxyl
radicals with an estimated half-life of 5 hours. It will also degrade with reaction
with atmospheric ozone with an estimated half-life of 7 days. Physical removal
from air can occur through wet and dry deposition. Exposure to norflurazon
can occur through dermal contact, inhalation, and ingestion. (SRC)
Probable Routes of Human Exposure:
Herbicides, such as norflurazon, can
be absorbed into the body by three routes: dermal contact, inhalation, and ingestion(1).
Artificial Pollution Sources:
Norflurazon's use as a herbicide(1)
will result in its release to the environment through various herbicidal applications(SRC).
Environmental Fate:
Terrestrial fate: In sandy loam soil, at 5, 20, and 35 deg C, 4-chloro-5-dimethylamino-2-(alpha,alpha,alpha-trifluoro-m-tolyl)-
3(2H)-pyridazinone dissipation was 10, 80 and 97 percent after 210 days and
was converted to its monomethyl and demethylated metabolites. At 20 and 35 deg
C, 4-chloro-5-dimethylamino-2-(a,a,a,-trifluoro-m-tolyl)-3(2H)-pyridazinone
exhihited a /half-life of/ = 50 and 9 days, respectively. The half-life of norflurazon
in soil was about 8 months. The demethylated metabolite of norflurazon
was observed.
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.
TERRESTRIAL FATE: In soil 50% loss occurs in 21-28 days according to soil
type and method of application.
TERRESTRIAL FATE: Using a structure estimation method based on molecular connectivity
indexes, the Koc for norflurazon can
be estimated to be about 5674(1). The Koc for norflurazon
can be estimated to be about 698 based on an experimental water solubility of
28 mg/L(3) and a regression derived equation(2). The Koc for norflurazon
has also been estimated to be 700(3). Koc has been experimentally determined
to be 3311(4). Another experimental value for Koc has been given as 1914(5).
According to a suggested classification scheme(6), these estimated and experimental
Koc values suggest that norflurazon
mobility in soil will be low to immobile. The trifluoromethyl group may enhance
the mobility of norflurazon(9). Norflurazon
adsorption increases, thereby decreasing mobility with increasing soil organic
matter and clay content(11). Sorption of norflurazon
on Candler fine sand increases with increasing ionic strength of electrolyte(7).
Sorption of norflurazon also varies
with the cation species in the electrolyte in the following order: Fe >>
Al = Cu > K = Ca = Mg = Na(7). The adsorption isotherm of norflurazon
appears to be curvilinear(8). It is suggested that the adsorption mechanism
may be due primarily to hydrophobic association of the organic molecule with
the soil organic matter surface(8). 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(12). The half-lives
estimated for norflurazon in soil are
30 and 90 days(4,11). Low volatilization but significant photolytic losses occurred
when norflurazon-treated soil coated
slides were exposed to ultraviolet or sunlight(10). Norflurazon
loss in runoff from residue trays with no crops present with Bosket sandy loam
soil at 1.1% slope was 4.4% when a rainfall of 3.8 cm in 30 minutes was applied
at 24 hours after application(13). No loss was reported for crop residue trays(13).
AQUATIC FATE: Based on an estimated Henry's Law constant of 2.84X10-10 atm-cu
m/mol(2,SRC) and a suggested classification scheme(1), norflurazon
will be essentailly non-volatile(SRC). Bioconcentration is not expected to be
an important fate process(SRC). Adsorption to sediment may be possible based
on Koc values of 698 to 5674(1-5,SRC).
ATMOSPHERIC FATE: Based on an experimental vapor pressure of approximately
2X10-8 mm Hg at 25 deg C(1), and a suggested calssification scheme(2), norflurazon
will exist in the vapor and particulate phases in the ambient atmosphere(SRC).
In the vapor phase, it will degrade in the atmosphere by reaction with photochemically
produced hydroxyl radicals with an estimated half-life of 5 hrs(3). It will
also degrade with atmospheric ozone with an estimated half-life of 7 days. Physical
removal of particulate norflurazon from
air is likely to occur through wet and dry deposition(SRC).
Environmental Biodegradation:
Microbial breakdown of norflurazon
is responsible for the disappearance from the soil environment(1).
Environmental Abiotic Degradation:
The rate constant for the vapor-phase reaction of norflurazon
with photochemically produced hydroxyl radicals has been estimated to be approximately
7.2X10-11 cu cm/molecule-sec at 25 deg C which corresponds to an atmospheric
half-life of about 5.4 hours at an atmospheric concn of 5X10+5 hydroxyl radicals
per cu cm(1,SRC). The reaction rate of norflurazon
with atmospheric ozone has been estimated to be 1.6X10-18 cu cm/molecule-second
which corresponds to an atmospheric half-life of 7 days at an ozone concentration
of 7X10+11 molecules/cu cm(1,SRC). Low volatilization but significant photolytic
losses occurred when norflurazon-treated
soil coated slides were exposed to ultraviolet or sunlight(2). Norflurazon
undergoes 25% degradation by ultraviolet light in 24 hours(3). Volatilization
and photodegradation are shown to be factors responsible for disappearance of
norflurazon when exposed on the soil
surface(3).
Environmental Bioconcentration:
Based upon an experimental water solubility of 28 mg/l(1), the BCF of norflurazon
can be estimated to be approximately 94 from a regression-derived equation(2).
This estimated BCF value suggests that bioconcentration in aquatic organisms
will not be an important fate process(SRC).
Soil Adsorption/Mobility:
Using a structure estimation method based on molecular connectivity indexes,
the Koc for norflurazon can be estimated
to be about 5674(1). The Koc for norflurazon
can be estimated to be about 698 based on an experimental water solubility of
28 mg/L(3) and a regression derived equation(2). The Koc for norflurazon
has also been estimated to be 700(3). Koc has been experimentally determined
to be 3311(4). Another experimental value for Koc has been given as 1914(5).
According to a suggested classification scheme(6), these estimated and experimental
Koc values suggest that norflurazon
mobility in soil will be low to immobile. Using a soil TLC study, the Rf for
norflurazon was determined to be 0.40(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, 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, 2.27 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).
Volatilization from Water/Soil:
Based on an experimental water solubility of 28 mg/l at 25 deg C(1) and an
experimental vapor pressure of 2X10-8 mm Hg at 25 deg C(1), the Henry's Law
constant for norflurazon can be calculated
to be 2.85X10-10 atm-cu m/mole(SRC). This value of Henry's Law constant indicates
that norflurazon is essentially non-volatile(2).
Environmental Water Concentrations:
SURFACE WATER: In a study of the Mississippi River, norflurazon
was detected in the Yazoo River (Mississippi) going into the Mississippi, and
in the Mississippi River below Vicksburg, MS, near St. Francisville, LA, and
below Belle Chasse, LA at 298, 51, 38, 30, and 27 ng/L(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).
DRINKING WATER: A study of 783 rural domestic wells and 566 community water
system wells (detection limit = 0.18 ug/L), and another study of 68,824 wells
in 45 states (detection limit not reported), did not detect norflurazon
in any samples(1,2).
Environmental Standards & Regulations:
FIFRA Requirements:
Tolerances are established for the combined residues of the herbicide norflurazon
(4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3-(2H)-pyridazinone)
and its desmethyl metabolite 4-chloro-5- (amino)-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3-(2H)-pyridazinone
in or on the following raw agricultural commodities: almonds (hulls); almonds
(meat); apricots; apples; asparagus; avocados; blackberries; blueberries; cattle
(fat, meat, mbyp); cherries; citrus fruit; cottonseed; cranberries; filberts;
goats (fat, meat, mbyp); grapes; hogs (fat, meat, mbyp); hops (green); horses
(fat, meat, mbyp); milk; nectarines; peanuts; peanuts (hay); peanuts (hulls,
vines); pears; pecans; plums (fresh prunes); poultry (fat, meat, mbyp); raspberries;
sheep (fat, meat, mbyp); soybeans; soybean forage; soybean hay; and walnuts.
A regulation is established for the combined residues of the herbicide norflurazon
(4-chloro-5-(methylamino)- 2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone)
and its desmethyl metabolite (4-chloro-5-amino-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone)
in dried hops when present therein as a result of its application to the growing
crop.
A regulation is established for the combined residues of the herbicide norflurazon
(4-chloro-5-(methylamino)- 2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone)
and its desmethyl metabolite (4-chloro-5-amino-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone)
in citrus molasses and dried citrus pulp when present therein as a result of
the application of the pesticide to the growing crop.
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.
Allowable Tolerances:
Tolerances are established for the combined residues of the herbicide norflurazon
(4-chloro-5-(methylamino)-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3-(2H)-pyridazinone)
and its desmethyl metabolite 4-chloro-5- (amino)-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3-(2H)-pyridazinone
in or on the following raw agricultural commodities: almonds (hulls), 1.0 ppm;
almonds (meat), 0.1 ppm; apricots, 0.1 ppm; apples, 0.1 ppm; asparagus, 0.05
ppm; avocados, 0.2 ppm; blackberries, 0.1 ppm; blueberries, 0.2 ppm; cattle
(fat, meat, mbyp), 0.1 ppm; cherries, 0.1 ppm; citrus fruit, 0.2 ppm; cottonseed,
0.1 ppm; cranberries, 0.1 ppm; filberts, 0.1 ppm; goats (fat, meat, mbyp), 0.1
ppm; grapes, 0.1 ppm; hogs (fat, meat, mbyp), 0.1 ppm; hops (green), 1.0 ppm;
horses (fat, meat, mbyp), 0.1 ppm; milk, 0.1 ppm; nectarines, 0.1 ppm; peanuts,
0.05 ppm; peanuts (hay), 5.50 ppm; peanuts (hulls, vines), 1.5 ppm; pears, 0.1
ppm; pecans, 0.1 ppm; plums (fresh prunes); poultry (fat, meat, mbyp), 0.1 ppm;
raspberries, 0.1 ppm; sheep (fat, meat, mbyp), 0.1 ppm; soybeans, 0.1 ppm; soybean
forage, 1.0 ppm; soybean hay, 1.0 ppm; and walnuts, 0.1 ppm.
A regulation is established for the combined residues of the herbicide norflurazon,
(4-chloro-5-(methylamino)- 2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone),
and its desmethyl metabolite, (4-chloro-5-amino-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-
pyridazinone), in dried hops at 3.0 ppm when present therein as a result of
its application to the growing crop.
A regulation is established for the combined residuesof the herbicide norflurazon,
(4-chloro-5-(methylamino)- 2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-pyridazinone),
and its desmethyl metabolite, (4-chloro-5-amino-2-(alpha, alpha, alpha-trifluoro-m-toyl)-3(2H)-
pyridazinone), in citrus molasses at 1.0 ppm and dried citrus pulp at 0.4 ppm
when present therein as a result of the application of the pesticide to the
growing crop.
Chemical/Physical Properties:
Molecular Formula:
C12-H9-Cl-F3-N3-O
Molecular Weight:
303.67
Color/Form:
Colorless crystalline solid
White crystalline solid
Crystals from alcohol
Odor:
Odorless
Melting Point:
117 deg C
Corrosivity:
Non-corrosive
Solubilities:
In water @ 23 deg C, 28 mg/l. In ethanol 142, acetone 50, xylene 2.5 (all
in g/l @ 25 deg C). Sparingly soluble in hydrocarbons.
Moderately soluble in ... hot ethanol.
Sol in water @ 25 deg C: 28 ppm
Vapor Pressure:
2X10-8 mm Hg at 25 deg C
Chemical Safety & Handling:
Fire Potential:
Nonflammable
Stability/Shelf Life:
Stable in aqueous solution @ pH 3-9 (<8% loss within 24 hr). ... Stable
upon storage (shelf life (@ 20 deg C) greater than or equal to 4 yr). ... Rapidly
degraded by sunlight.
Stable under alkaline and acid conditions ... but susceptible to light.
Disposal Methods:
SRP: At the time of review, criteria for land treatment or burial (sanitary
landfill) disposal practices are subject to significant revision. Prior to implementing
land disposal of waste residue (including waste sludge), consult with environmental
regulatory agencies for guidance on acceptable disposal practices.
Occupational Exposure Standards:
Manufacturing/Use Information:
Major Uses:
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.
To control grasses and broadleaf weeds in grape vines, cotton and soybeans
... , control of grasses, sedges, and broadleaf weeds in cranberries.
General Manufacturing Information:
Soil applied herbicide for preplant incorporated, preemergence, or split applications.
Selective pre-emergent herbicide which inhibits carotenoid biosynthesis in
susceptible species.
Formulations/Preparations:
'Evital', granules (50 g ai/kg); 'Solicam
Rapid' ... 'Solicam', 'Zorial
wettable powder (800 g/kg). Mixture includes: 'Telok',
granules (40 g norflurazon + 20 g simazine/kg)
Dry flowable, granular; in US 80% instant dry flowable
Laboratory Methods:
Analytic Laboratory Methods:
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.
Special References:
Synonyms and Identifiers:
Synonyms:
H-52,143
**PEER REVIEWED**
H-9789
**PEER REVIEWED**
4-Chloro-5-methylamino-2-(3-trifluoromethylphenyl)pyridazin-3-one
**PEER REVIEWED**
4-Chloro-5-(methylamino)-2-(3-(trifluoromethyl)phenyl)-3(2H)-pyridazinone
**PEER REVIEWED**
4-Chloro-5-(methylamino)-2-(alpha,alpha,alpha-trifluoro-m-tolyl)-3(2H)- pyridazinone
**PEER REVIEWED**
4-Chloro-5-methylamino-2-(alpha,alpha,alpha-trifluoro-m-tolyl)pyridazin-3(2H)-
one
**PEER REVIEWED**
Evital
**PEER REVIEWED**
Evitol
**PEER REVIEWED**
Norflurazone
**PEER REVIEWED**
SAN 9789
**PEER REVIEWED**
Solicam
**PEER REVIEWED**
Solicam Rapid
**PEER REVIEWED**
Telok
**PEER REVIEWED**
1-(3-Trifluoromethylphenyl)-4-methylamino-5-chloropyridazone
**PEER REVIEWED**
Zorial
**PEER REVIEWED**
Formulations/Preparations:
'Evital', granules (50 g ai/kg); 'Solicam
Rapid' ... 'Solicam', 'Zorial
wettable powder (800 g/kg). Mixture includes: 'Telok',
granules (40 g norflurazon + 20 g simazine/kg)
Dry flowable, granular; in US 80% instant dry flowable
Administrative Information:
Hazardous Substances Databank Number: 6845
Last Revision Date: 20010809
Last Review Date: Reviewed by SRP on 9/14/1995
Update History:
Complete Update on 08/09/2001, 1 field added/edited/deleted.
Complete Update on 05/15/2001, 1 field added/edited/deleted.
Complete Update on 10/18/2000, 5 fields added/edited/deleted.
Field Update on 06/12/2000, 1 field added/edited/deleted.
Field Update on 06/12/2000, 1 field added/edited/deleted.
Field Update on 02/08/2000, 1 field added/edited/deleted.
Field Update on 02/02/2000, 1 field added/edited/deleted.
Field Update on 09/21/1999, 1 field added/edited/deleted.
Field Update on 08/26/1999, 1 field added/edited/deleted.
Field Update on 06/03/1998, 1 field added/edited/deleted.
Field Update on 03/10/1998, 1 field added/edited/deleted.
Field Update on 11/01/1997, 1 field added/edited/deleted.
Complete Update on 02/03/1997, 1 field added/edited/deleted.
Complete Update on 05/14/1996, 1 field added/edited/deleted.
Complete Update on 03/25/1996, 15 fields added/edited/deleted.
Field Update on 02/01/1996, 1 field added/edited/deleted.
Field Update on 08/21/1995, 1 field added/edited/deleted.
Complete Update on 04/25/1994, 28 fields added/edited/deleted.