E X T O X N E T
Extension Toxicology Network
A Pesticide Information Project of Cooperative Extension Offices of
Cornell University, Michigan State University, Oregon State University, and
University of California at Davis. Major support and funding was provided
by the USDA/Extension Service/National Agricultural Pesticide Impact
Publication Date: 9/95
TRADE OR OTHER NAMES
Product names include Talstar, Bifenthrine, Brigade, Capture, FMC
54800, OMS3024, Torant (with Clofentezine), and Zipak (with Amitraz) (1,
Bifenthrin is a Restricted Use Pesticide (RUP). It is for retail
sale to and use only by certified applicators or persons under their
direct supervision. It is only for the uses covered by the applicators
certification (2). In the U.S., bifenthrin is registered for use on
greenhouse ornamentals and cotton (4).
Bifenthrin is a member of the pyrethroid chemical class. It is an
insecticide and acaricide which affects the nervous system and causes
paralysis in insects (1, 2). It is very highly toxic to fish and aquatic
organisms (2, 3). The U.S. EPA has classified bifenthrin as Toxicity
Class II-moderately toxic. Products containing bifenthrin must bear the
SIGNAL WORD: WARNING. It is available as an emulsifiable concentrate or
a wettable powder (4).
Bifenthrin is moderately toxic to mammals when ingested. Large
doses may cause incoordination, tremor, salivation, vomiting, diarrhea,
and irritability to sound and touch (10). The dose at which half of the
test animal die, the LD50, for bifenthrin is about 54 mg/kg in female
rats and 70 mg/kg in male rats (5). The LD50 for rabbits whose skin is
exposed to bifenthrin is greater than 2,000 mg/kg (2). Bifenthrin does
not sensitize the skin of guinea pigs (3). Although it does not cause
inflammation or irritation on human skin, it can cause a tingling
sensation which lasts about 12 hours. It is virtually non-irritating to
rabbit eyes (10).
The dose at which no toxic effect of bifenthrin is observed on the
mother (maternal toxicity NOEL) is 1 mg/kg/day for rats and 2.67
mg/kg/day for rabbits. At higher doses, test animals had tremors (9).
The dose at which no toxic effect is observed on development
(developmental toxicity NOEL) is 1 mg/kg/day for rats and is greater
than 8 mg/kg/day for rabbits (2).
Bifenthrin does not demonstrate any teratogenic effects at the
highest levels tested (100 ppm, approximately 5.5 mg/kg/day) in a two-
generational study in rats (5).
Evidence of mutagenic effects from exposure to bifenthrin are
inconclusive. Studies of mouse white blood cells were positive for gene
mutation. However, other tests of bifenthrin's mutagenic effects,
including the Ames test and studies in live rat bone marrow cells, were
There was no evidence of cancer in a 2-year study of rats who ate
as much as 10 mg/kg/day of bifenthrin. However, an 87 week feeding study
of mice with doses of 7, 29, 71, and 86 mg/kg showed a significantly
higher, dose related trend of increased tumor incidence in the male
urinary bladder (5, 9). The incidence was significantly increased at 86
mg/kg/day. Also, females had higher incidences of lung cancer than the
controls at doses of 7 mg/kg and higher (9). The EPA has classified
bifenthrin as a class C carcinogen, a possible human carcinogen (2, 5).
Pyrethroids are poisons that affect the electrical impulses in
nerves, over-stimulating nerve cells causing tremors and eventually
causing paralysis (2).
Fate in Humans and Animals
Bifenthrin is absorbed through intact skin when applied topically
(10). It undergoes similar modes of breakdown within animal systems as
other pyrethroid insecticides. In mammals, bifenthrin is rapidly broken
down and promptly excreted. Rats treated with 4 to 5 mg/kg, excreted 70
% in the urine and 20% in the feces within 7 days. After 7 days, the
remaining bifenthrin was found accumulated in tissues with high fat
content such as the skin and fat in males and females and the ovaries of
females (9). Bifenthrin is less toxic to warm-blooded animals, such as
mammals, than to cold-blooded animals (10).
Effects on Birds
Bifenthrin is moderately toxic to many species of birds (1). The
dietary concentration (8 day) at which half of the test animals die, the
LC50, is 1,280 ppm for mallard ducks and 4,450 ppm for bobwhite quail
(7). The acute oral LD50 is 1,800 mg/kg for bobwhite quail and 2,150
mg/kg for mallard ducks. There is concern about possible bioaccumulation
in birds (5).
Effects on Aquatic Organisms
Bifenthrin is very highly toxic to fish, crustaceans and aquatic
animals (1, 2). The LC50 after a 96-hour exposure is 0.00015 mg/l for
rainbow trout, 0.00035 mg/l for bluegill, and 0.0016 mg/l for Daphnia
(4, 5). Because of its low water soilubility and high affinity for
soil, bifenthrin is not likely to be found in aquatic systems.
Effects on Other Animals (Nontarget species)
Bifenthrin is toxic to bees (3).
Breakdown of Chemical in Soil & Groundwater
Bifenthrin does not move in soils with large amounts of organic
matter, clay and silt. It also has a low mobility in sandy soils that
are low in organic matter. Bifenthrin is relatively insoluble in water,
so there are no concerns about groundwater contamination through
leaching. It's half-life in soil, the amount of time it takes to degrade
to half of its original concentration, is 7 days to 8 months depending
on the soil type and the amount of air in the soil (2, 3).
Breakdown of Chemical in Vegetation
Bifenthrin is not absorbed by plant foliage, nor does it
translocate in the plant (5).
PHYSICAL PROPERTIES AND GUIDELINES
Bifenthrin is an off-white to pale tan waxy solid with a faint,
slightly sweet smell (5). It is photostable, stable to hydrolysis, has
minimal volatility, and is stable in storage. It has a negative
temperature coefficient, so it works better at lower temperatures (8).
|CAS #: ||82657-04-3
|Chemical Name: ||(2-methyl-1, 1-biphenyl-3-y1)-methyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl cyclopropanecarboxylate
|Melting point: ||68-70.6 degrees C (5)
|Solubility in water: ||0.1 mg/l (4)
|Solubility in solvents: ||Bifenthrin is soluble in methylene chloride, acetone, chloroform, ether and toluene. It is slightly soluble in heptane and methanol (4).
|Partition Coefficient (octonal/water) ||Kow = 1,000,000 (4)
|ADI: ||0.015 mg/kg (4)
|NOEL: ||2.5 mg/kg/day (rat); 1.5 mg/kg/day (dog) (2, 6)
|RfD: ||0.015 mg/kg/day (6)
Agricultural Chemicals Group
2000 Market Street
Philadelphia, PA 19103
Review by Basic Manufacturer:
Comments solicited: October, 1994
Briggs, Shirley. 1992. Basic Guide to Pesticides. Hemisphere
Publishing. Washington, DC.
Walker, M. M. and L. H. Keith. 1992. EPA's Pesticide Fact Sheet
Database. Lewis Publishers. Boca Raton, FL.
Meister, R.T. 1992. Farm Chemicals Handbook '92. Meister
Publishing Company. Willoghby, OH.
The Agrochemicals Handbook, Third Edition. 1994. Royal Society of
Chemistry Information Systems, Unwin Brothers Ltd. Surrey, England.
U.S. EPA Office of Pesticides and Toxic Substances. 1988. Fact
Sheet No.177 Bifenthrin. U.S. EPA. Washington, DC.
U.S. Department of Health and Human Services. 1988. U.S. EPA
Integrated Risk Information System (IRIS) database. HHS. Washington, DC.
Meister, R.T. 1994. Farm Chemicals Handbook '94. Meister
Publishing Company, Willoughby, OH.
Ware, G.W. 1986. Fundamentals of Pesticides - A Self Instruction
Guide, Second edition. Thomson Publications. Fresno, CA.
U.S. EPA. 1987. Toxchem No. 463F, CORE grade. Document Number
005731, EPA Accession Number 264638, 404151-02 and 264639. U.S. EPA,
U.S. Department of Health and Human Services. 1993. Hazardous
Substance Data Base. HHS. Washington, DC.