United State* Office of Pesticides end Toxic Substances
Environmental Protection Office of Pesticide Program* (TS-766C)
Agency Washington, DC 20460
vvEPA Pesticide
Fact Sheet
Name of Chemical:
Reason for Issuance: New Chemical Registration
Date Issued: March 1986
Fact Sheet Number: 81
1. Description of chemical
Generic name: l-methyl-3-phenyl-5-[3-(trlfluoromethyl)phenyl]-
4[lH]-pyridlnone
Common name: Fiuridone
Trade name: Sonar
EPA Shaughnessy code: 112900-6
Year of Initial registration: 1986
Pesticide type: Aquatic herbicide
U.S. and foreign producers: Elanco Products Company
2. Use patterns and formulations
Application sites: freshwater ponds, lakes, reservoirs, drainage
canals, Irrigation canals, rivers
Types of formulations: aqueous suspension; pellet
Types and methods of application: surface spray, weighted-hose dragged
near bottom; broadcast (pellet)
Application rates: 0.5 lb ai/surface acre — 4.0 Ib ai/surface acre
Usual carrier: water
3. Science findings
Summary science statement: Supporting data base for flurldone registration
and tolerance proposals supporting aquatic use is complete and acceptable
except for a second species (rat) teratology study. Original study sub-
mitted did not produce teratogenlc response at any level tested. The study,
however, is not adequate for regulatory purposes because the highest
dose tested did not produce frank maternal toxicity or fetotoxlcity.
The study is presently being repeated.
Chemical characteristics; Fiuridone is a white (to offwhite) crystalline
solid with no odor. The melting point is 15^-155° C. The flashpoint
for the aqueous suspension formulation is greater than 200° C. Fiuridone
is not corrosive to application equipment.
Toxicologlcal characteristics;
Acute toxicology: Technical fluridone is in Category IV for acute
oral effects in the rat and Is moderately toxic through acute inhalation
exposure. Eye irritation potential has been demonstrated as moderate
to severe (Cat. Ill and Cat. II). The aqueous suspension and pellet
formulations are in Cat. Ill for oral, dermal, skin, and eye Irritation
effects.
-------
Chronic toxicology : A complete-, acceptable chronic
toxicity data base Is available, except for a rat tera-
tology 8tudy (second species). A valid rabbit teratology
study indicates no teratogenic re8ponse up to a dose
level of 300 mg/kg/day. Fluridone Is not considered to
have produced an oncogenic response in the mouse or rat.
Mutagenicity assays submitted do not indicate genotoxic
potential, gene mutation, or structural chromosoma]. aberration.
Physiological and biochemical behavioral characteristics:
Fluridone is a systemic herbicide; it is absorbed from
water by plant shoots and. from hydrosoll by roots.
Inhibits carotenold synthesis which enhances degradation
of chlorophyll, producing white (chiorotic) growing points
in susceptible plants.
Environmental characteristics:
Degradation : Fluridone Is stable to hydrolysis. It will
photodegrade (half-life 314 hours in natural pond water).
Persistence : Under anaerobic aquatic conditions, fluridone
has a half-life of 9 months. Half-life for fl ridone In
water is estimated to be 20 days; for hydrosoll, 90 days.
Bloaccumu].ation : Fluridone has a low potential for
bloaccumulation in fish.
Ecological characteristics:
Avian studies : Acute oral (bobwhite quail) > 2000 mg/kg
(slightly toxic). Aviari dietary (bobwhite quail and
mallard duck) > 5000 ppm. No Impairment on reproduction
for above species up to 1000 ppm dietary exposure.
Aquatic species studies:
Daphnia magna 48-hour acute is 6.3 mg/L (moderately toxic)
Bluegill sunfish 96—hour acute is 12 mg/L (moderately toxic)
Rainbow trout 96-hour acute is 11.7 mg/L (moderately toxic)
Sheepshead minnow 96—hour acute is 10.91 mg/L (moderately
toxic)
.yster embryo-larvae 48—hour acute Is 16.51 mg/L (moderately
toxic)
Maximum acceptable theoretical concentration (MATC) va1ue
for fathead minnow (second generation fry) was calculated
to be > 0.148 < 0.96 mg/L. No treatment related effects
were observed at or below 0.148 mg/L. Total length of 3
day-old fry was reduced at 2 mg/L f’lurldone.
-------
Potintlal - oblems for endangered-species :
Acute and MATC values indicate a potential hazard
for aquatic. organisms in shallow areas at higher treatment
rates described on the label. Formal consultation with
Office of Endangered Species (OES) has been Initiated.
To minimize hazard, label directions provide for use of
lowest listed rates for shallow areas and consultation
with Fish and Game agency or U.S. Fish and Wildlife
Service if questions arise concerning aquatic resources
In the area to be treateçl.
Tolerances proposed :
A tolerance is proposed for residues of the herbicide
fluridone (l methyl—3_pheny].5_ [ 3_(trIf1uoromethy1)phenylJ_
(1H)—pyridinone) and its metabolite (1-methyl—3—(L-.
hYdroxyphenyl)—5_ [ 3_(tr lf luoromethy l)PhenylJ_jl( 1 H)_
pyridinone) In fish at 0.5 ppm.
A tolerance is proposed for residues of the herbicide
fluridone in the following raw agricultural commodities:
Commodity Parts Per Million
Cattle, fat 0.05
Cattle, kidney 0.1
Cattle, liver 0.1
Cattle, meat byproducts 0.05
Cattle, meat (except 0.05
liver and kidney)
Eggs 0.05
Goats, fat 0.05
Goats, kidney 0.1
Goats, liver 0.1
Goats, meat byproducts 0.05
Goats, meat (except 0.05
liver and kidney)
Hogs, fat 0.05
Hogs, kidney o.i
Hogs, liver 0.1
Hogs, meat byproducts 0.05
Hogs, meat (except 0.05
liver and kidney)
3
-------
Horses, fat 0.05
Horses, kidney 0.1
Horses, liver 0.1
Horses, meat byproducts 0.05
Horses, meat (except 0.05
liver and kidney)
Milk 0.05
Poultry, fat 0.05
Poultry, kidney 0.1
Poultry, liver 0.1
Poultry, meat byproducts 0.05
Poultry, meat (except 0.05
liver and kidney)
Sheep, fat 0.05
Sheep, kidney 0.1
Sheep, liver 0.1
Sheep, meat byproducts 0.05
Sheep, meat (except 0.05
liver and kidney)
Tolerances are proposed in the following irrigated crops
and crop groupings for residues of the herbicide fluridone
resulting from use of irrigation water containing residues of
0.15 ppm following applications on or around aquatic sites.
Where tolerances are established at higher levels from other
uses of fluridone on the following crops, the higher tolerance
also applies to residues in the irrigated commodity. The
tolerances follow:
Commodity Parts Per Million
Avocados 0.1
Citrus 0.1
Cottonseed 0.1
Cucurbits 0.1
Forage Grasses 0.15
Forage Legumes 0.15
Fruiting vegetables o.i
Grain crop 0.1
Hops 0.1
Leafy vegetables
Nuts 0.1
Pome fruit 0.1
Root crops — vegetables o.i
Seed and pod vegetables o.i
Small f ruit 0.1
Stone fruit 0.1
-------
aaed on the NOEL of 8 rn/kg/day In the chronic rat
feeding study and a 100—fold safety factor, the acceptable
daily intake (ADI) has been set at 0.08 mg/kg/day with a
maximum permissible intake (MPI) of 11.8 mg/day for a 60-kg
person. There are no previously established tolerances for
this herbicide.
The Agency is designating an acceptable residue level
for fluridone In potable water at 0.15 ppm. This concentra-
tion reflects the maximum application rate for the herbicide
registration(s) issued pursuant to FIFRA. Consumption of
water Is estimated at 2.0 liters per day for a 60-kg adult.
These tolerances and the acceptable residue level In potable
water result in a theoretical maximum residue contribution
of 0.14112 mg/day in a 1.5—kg diet (including 2 liters of
water) and use 8.57 percent of the ADI.
No Mexican, Canadian, or Codex maximum residue levels
have been established. Residue studies are adequate to
support the proposed tolerances. Plant and animal metabolism
is adequately understood and adequate analytical methods are
available to enforce the tolerance levels. The residue of
concern in drinking water is parent compound, I.e., fluridone.
)4• Summary of Regulatory Position and Rationale
Risk/benefit review : None of the risk criteria set forth
In Title 140 Code of Federal Regulations §162.11 have been
exceeded for fluridorie.
Fluridone has been proposed only for direct application
to aquatic sites. No ground water contamination issue is
associated with this use.
5. Summary of Major Data Gaps
An additional rat (second species) teratology is underway.
Schedule for submIssion: July 1, 1986.
6. Contact Person at EPA
Richard F. Mountfort
Product Manager (23)
Environmental Protection Agency
1401 M St. SW.
Washington, DC 201460
(703) 557—1830
DISCLAIMER: The information presented In this Chemical
Information Fact Sheet is for informational purposes only and
may not be used to fulfill data requirements for pesticide
registration and reregistration.
5-
------- |