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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 Assessment Program.


Publication Date: 9/93


Trade names for commercial products containing this herbicide include Tornado, Fusilade 2000, Fusilade Five, and Fusilade Super. The compound is compatible with a wide variety of other herbicides. The compound is also found in formulations with the herbicide fomesafen.


Fluazifop-p-butyl is a selective phenoxy herbicide used for postemergence control of annual and perennial grass weeds. It is used on soybeans and other broad-leaved crops such as carrots, spinach, potatoes, and ornamentals.

Fluazifop-p-butyl is a general use pesticide.

NOTE: This herbicide is a different compound than either fluazifop or fluazifop butyl. Both the chemical structures and the toxicities of these compounds are different. Fluazifop-p-butyl formulations can contain some fluazifop-butyl.



Fluazifop-p-butyl is a slightly toxic compound which carries the signal word CAUTION on its label. A single dose of the formulated compound (Fusilade 2000) can cause severe stomach and intestine disturbance. Ingestion of large quantities may cause problems in the central nervous system such as drowsiness, dizziness, loss of coordination and fatigue. Breathing small amounts of the product may cause vomiting and severe lung congestion. This may ultimately lead to labored breathing, coma and death (1).

The acute oral LD50 of fluazifop-p-butyl is 3,680 for male rats and 2,451 for female rats. The dermal LD50 for the compound is greater than 2,450 in rabbits. This value indicates that the compound has a low to moderate toxicity when in contact with the skin. It is only a mild skin and eye irritant and causes no skin sensitization (2).


Rats fed small amounts of fluazifop-p-butyl for three months developed no compound induced effects at doses at or below 10 mg/kg.

Reproductive Effects

No information is currently available.

Teratogenic Effects

No information is currently available.

Carcinogenic Effects

No information is currently available.

Mutagenic Effects

No information is currently available.

Organ Toxicity

No information is currently available.

Fate in Humans and Animals

No information is currently available.


Fluazifop-p-butyl is practically non-toxic to mallard ducks. Its acute oral LD50 in mallards is greater than 3,528 mg/kg. Values for other species are not currently available, thus its overall toxicity to birds, invertebrates, and mammals cannot be adequately assessed. The compound does, however, have a very low toxicity to bees. Oral and contact LD50s for bees are greater than 0.20 mg/bee (2).


Fluazifop-p-butyl breaks down rapidly in moist soils. Its half- life in moist conditions is generally less than a week (2). The major degradation product of fluazifop-p-butyl will also break down fairly rapidly. Its half-life is around three weeks.

Fluazifop-p-butyl is actively taken up by plants and translocated throughout the plant. The compound accumulates in the actively growing regions of the plant (shoots, root rhizomes, stolons of grass) where it interferes with the plant cell's ability to produce energy. In plants, fluazifop-p-butyl is rapidly broken down in the presence of water to fluazifop-p.

Exposure Guidelines:

NOEL (rat): 10 mg/kg

Physical Properties:

CAS #: 69806-50-4
Chemical name: (R)2-[4[445[-(trifluoro-methyl)-2-pyridinyl]oxy]-phenoxy] propanoate
Chemical class/use: Phenoxy, trifluoromethyl, pyridine herbicide
Solubility in water: 1 mg/l
Solubility in other solvents: soluble in most organic solvents
Melting point: 5 degrees C
Vapor Pressure: 0.054 mPa at 20 degrees C
Stability: Compound is stable to UV light; decomposes at 210 degrees C


Zeneca Ag Products
Wilmington, Delaware 19897
Telephone 800-323-8633

Review by Basic Manufacturer:

Comments solicited: December, 1992
Comments received:


  1. Material Safety Data Sheet. ICI Americas Inc. Fusilade 2000.
  2. The Agrochemicals Handbook. 1991. The Royal Society of Chemistry. Cambridge, England.