E X T O X N E T
Extension Toxicology
Network
Pesticide Information Profiles
A Pesticide Information Project of Cooperative Extension Offices of Cornell
University, Oregon State University, the University of Idaho, and the University
of California at Davis and the Institute for Environmental Toxicology, Michigan
State University. Major support and funding was provided by the USDA/Extension
Service/National Agricultural Pesticide Impact Assessment Program.
EXTOXNET primary files maintained and archived at Oregon State University
Revised 9/95.
BIFENTHRIN
TRADE OR OTHER NAMES: Product names include
Talstar, Bifenthrine, Brigade, Capture, FMC 54800, OMS3024, Torant (with
Clofentezine), and Zipak (with Amitraz) (61, 11).
REGULATORY STATUS: 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 (11). In the U.S., bifenthrin is registered for
use on greenhouse ornamentals and cotton (12).
INTRODUCTION: 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 (61, 11). It is very highly toxic
to fish and aquatic organisms (11, 62). 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 (12).
TOXICOLOGICAL EFFECTS
- Acute Toxicity: Bifenthrin is moderately toxic to mammals
when ingested. Large doses may cause incoordination, tremor, salivation,
vomiting, diarrhea, and irritability to sound and touch (68). 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 (63). The LD50 for rabbits whose skin
is exposed to bifenthrin is greater than 2,000 mg/kg (11). Bifenthrin does not
sensitize the skin of guinea pigs (62). 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
(68).
- Chronic Toxicity: No information Available.
- Reproductive Effects: 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 (67). 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 (11).
- Teratogenic Effects: 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 (63).
- Mutagenic Effects: 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 bifenthrinÕs
mutagenic effects, including the Ames test and studies in live rat bone marrow
cells, were negative (11).
- Carcinogenic Effects: 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 (63, 67). 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 (67). The EPA has classified
bifenthrin as a class C carcinogen, a possible human carcinogen (11, 63).
- Organ Toxicity: Pyrethroids are poisons that affect the
electrical impulses in nerves, over-stimulating nerve cells causing tremors
and eventually causing paralysis (11).
- Fate in Humans and Animals: Bifenthrin is absorbed
through intact skin when applied topically (68). 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 (67). Bifenthrin is less toxic to warm-blooded animals, such as
mammals, than to cold-blooded animals (68).
ECOLOGICAL EFFECTS
- Effects on Birds: Bifenthrin is moderately toxic to many
species of birds (61). 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 (65). 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 (63).
- Effects on Aquatic Organisms: Bifenthrin is very highly
toxic to fish, crustaceans and aquatic animals (61, 11). 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 (12, 63). 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 (62).
ENVIRONMENTAL FATE
- 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. ItÕs 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 (11, 62).
- Breakdown of Chemical in Vegetation: Bifenthrin is not
absorbed by plant foliage, nor does it translocate in the plant (63).
PHYSICAL PROPERTIES AND GUIDELINES: . 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 (66).
Physical Properties:
- Appearance: Bifenthrin is an off-white to pale tan waxy
solid with a faint, slightly sweet smell (63)
- Chemical Name:
(2-methyl-1,1-biphenyl-3-y1)-methyl-3-(2-chloro-3,3,3-trifluoro-1-propenyl)-2,2-dimethyl
cyclopropanecarboxylate
- CAS Number: 82657-04-3
- Molecular Weight: 422.9
- Water Solubility: 0.1 mg/l (12)
- Solubility in Other Solvents: Bifenthrin is soluble in
methylene chloride, acetone, chloroform, ether and toluene. It is slightly
soluble in heptane and methanol (12).
- Melting Point: 68-70.6 degrees C (63)
- Vapor Pressure: Not Available
- Partition Coefficient: >6
- Adsorption Coefficient: octonal/water) Kow = 1,000,000
(12)
Exposure Guidelines:
- ADI: 0.015 mg/kg (12)
- MCL: Not Available
- RfD:0.015 mg/kg/day (64)
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
- NOEL: 2.5 mg/kg/day (rat); 1.5 mg/kg/day (dog) (11, 64)
BASIC MANUFACTURER:
FMC Corporation
Agricultural Chemicals Group
2000 Market
Street
Philadelphia, PA 19103
- Telephone: 215-299-6000
- Emergency: 800-331-3148
REFERENCESReferences for the information in this PIP
can be found in Reference List Number 2
DISCLAIMER: The information in this profile
does not in any way replace or supersede the information on the pesticide
product label/ing or other regulatory requirements. Please refer to the
pesticide product label/ing.