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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
TRADE OR OTHER NAMES: Product names include Aazdieno, Acarac, Amitraze, Baam, Edrizan, Mitac, Maitac,
Triatox, Triatix, Vapcozin Taktic, Triazid, Topline, Tudy, Ectodex, Garial, Danicut, Ovidrex, Acadrex, Bumetran, and
REGULATORY STATUS: Amitraz is registered for use on pears, cattle, hogs, and cotton (224). It is not permitted on
apples to prevent its residues in processed apples or meat producing animals which consume apple processing waste (211).
Amitraz was a restricted use pesticide in 1985 because some studies showed it causes cancer in mice. But re-evaluation of
the evidence has led to the current classification of Amitraz as an unrestricted or General Use Pesticide (GUP) (230).
Amitraz is available in an emulsifiable concentrate, wettable powder, or a pour-on powder.
INTRODUCTION: Amitraz is a triazapentadiene compound, a member of the amidine chemical family (1). It is an
insecticide and acaricide used to control red spider mites, leaf miners, scale insects, and aphids. On cotton it is used to
control bollworms, white fly, and leaf worms. On animals it is used to control ticks, mites, lice and other animal pests
(207,225).The EPA classifies Amitraz as Class III - slightly toxic. However, products containing it bear the SIGNAL
WORD: CAUTION (224, 230).
- Acute Toxicity: Amitraz is slightly toxic to mammals if ingested orally (226). The dose of Amitraz that is lethal to half
of the test animals that ingest it is called the median lethal dose, or the LD50. The oral LD50 is 523-800 mg/kg for
amitraz in rats (223, 211, 224, 228). The oral LD50 is greater than 1,600 mg/kg for mice. Dermal exposure results in an
LD50 of greater than 1,600 mg/kg for rats and greater than 200 mg/kg for rabbits (1, 224, 22). The Lethal Concentration
50 or LC50 is the concentration of the chemical in air or water that kills half of the experimental animals exposed to it.
The inhalation LC50 (6 hours) of amitraz for rats is 65 mg/l of air. Amitraz is not a skin irritant and does not sensitize
skin (1). Signs of acute amitraz poisoning in male and female rats treated with 440 mg/kg and 365 mg/kg respectively,
include coolness to touch, reduced spontaneous activity, episodes of increased induced activity such as aggression in
response to handling, and signs of general debilitation. Amitraz also may produce a slowly reversible emaciation in
- Chronic Toxicity: In two-year feeding trials, rats who received 50 mg/kg/day in their diet and dogs who received 0.25
mg/kg/day of amitraz did not show any ill-effects (1).
- Reproductive Effects: Doses of 200 mg/kg/day of amitraz for ten weeks decreased fertility in male and female rats.
Female mice treated orally for 5 days with 50 mg/kg/day of amitraz and then mated showed a slight increase in loss of
fetuses and a decrease in the number of living offspring. When male mice were given 50 mg/kg/day of amitraz orally for
5 days and then mated, the resulting embryos were significantly less likely to grow in the mother's uterus. Female mice
who received 400 mg/kg/day of amitraz in their diet for up to 33 weeks, showed a significant increase in the time they
were sexually receptive (227). The highest dose of amitraz which has no observable effect on the death of unborn rats
(fetotoxic NOEL) is 3 mg/kg/day. The highest dose of amitraz that does not cause an observable effect in the death of rat
embryos (Embryotoxic NOEL) is 5 mg/kg/day (228). Rats who received 12 mg/kg/day of amitraz from day one of
pregnancy until the young were weaned at 21 days old had a reduced number of young born and alive at day four (227).
Rabbits who received 25 mg/kg/day of amitraz from days 6 to 18 of pregnancy had fewer and smaller litters (223).
Although there have been reproductive effects observed in laboratory animals at some dose levels, likely human
exposures are very much less than those which produced effects. These effects are unlikely in humans under normal
- Teratogenic Effects: In one study, rats treated with 12 mg/kg/day of amitraz from days 8 to 20 of pregnancy, the
offspring were heavier but had less bone development than the offspring of untreated rats (227). However, an EPA study
indicates that the highest dose at which amitraz has no observable effect on test rats' offspring (teratogenic NOEL) is 12
mg/kg/day (228). The teratogenic NOEL of rabbits is 25 mg/kg/day (223). These studies indicate that high doses of
amitraz exposure during pregnancy produced adverse effects in laboratory animals. Likely human exposures are very
much less than those which produced effects, and these effects are unlikely in humans under normal circumstances.
- Mutagenic Effects: A variety of tests indicate that amitraz is not mutagenic and does not cause damage to DNA (227).
- Carcinogenic Effects: Long term feeding studies show that amitraz is not carcinogenic in rats. However, it can cause
tumors in female mice (227). Amitraz causes an increase in tumors of the lungs and lymph nodes in female mice, but not
males, at 57 mg/kg/day over 20 months. A two-year study of female mice also showed an increase in tumors of the liver
(hepatocellular tumors) at 57 mg/kg/day of amitraz (224, 207). Because amitraz causes cancer in female mice, but not
male mice or male or female rats, it is unclassifiable as to human carcinogenicity (229).
- Organ Toxicity: At high doses, amitraz can reduce the function of the hypothalamus, which helps regulate the
metabolism by controlling hormone release in the body (224). A daily dose of 200 mg of amitraz per kilogram of body
weight for ten weeks causes decreased growth and food consumption (227).
- Fate in Humans and Animals: Available data suggest that amitraz, following absorption into the blood, is not readily
absorbed into tissues, and is mostly excreted unchanged via the urine (1, 224, 227).
- Effects on Birds: Amitraz is slightly toxic to birds. The dietary LC50 (8 day) is 7,000 mg/kg for mallard ducks and
1,800 mg/kg for Japanese quail (1, 226). The oral LD50 for bobwhite quail is 788 mg/kg (211). Amitraz may affect
reproduction in birds. The avian reproductionNOEL is less than 40 ppm (224).
- Effects on Aquatic Organisms: Amitraz is moderately toxic to fish (211, 224, 207). The LC50 (96-hour exposure) is
1.3 mg/l for bluegill sunfish and 3.2-4.2 mg/l for harlequin fish. For a 48-hour exposure of rainbow trout, a cold water
species, the LC50 is 2.7-4.0 mg/l (1). Daphnia, a fresh water invertebrate, exhibited toxic effects at 35 ppb of amitraz in
- Effects on Other Animals (Nontarget species): Amitraz is relatively non-toxic to bees (207, 226). The LD50 is 12
micrograms per bee by ingestion and 3.6 mg/l by direct spraying (1).
- Breakdown of Chemical in Soil: Amitraz is broken down rapidly in soil containing oxygen. The half-life in soil, the
amount of time needed for the chemical to degrade to half its original concentration, is less than one day. Degradation
occurs more rapidly in acidic soils than in alkaline or neutral soils (1).
- Breakdown of Chemical in Vegetation: Reports indicate that amitraz may cause crop injury to young peppers and
pears during high temperature conditions (207).
PHYSICAL PROPERTIES AND GUIDELINES: . It is non-corrosive and stable to heat. UV light seems to have little
effect on its stability. Slow decomposition occurs when amitraz is stored for prolonged periods under moist conditions (1).
- Appearance: Amitraz is a straw colored crystalline solid and odorless
- Chemical Name: N,N'-[(methylimino) dimethylidyne]di-2,4-xylidine
- CAS Number: 33089-61-1
- Molecular Weight: 221.04
- Water Solubility: ca. 1 mg/l (211). Soluble in common organic solvents including acetone, toluene, and xylene (211)
- Solubility in Other Solvents: Not Available
- Melting Point: 86-87 degrees C (1)
- Vapor Pressure: 0.051 mPa at 20 degrees C (1)
- Partition Coefficient: (octanol/water) Kow = 316,000 (1)
- Adsorption Coefficient: Not Available
- ADI: 0.003 mg/kg (human) (224).
- MCL: Not Available
- RfD: 0.0025 mg/kg/day (229).
- PEL: Not Available
- NOEL: 0.25 mg/kg/day (dog); 3 mg/kg/day (rat) (229).
- HA: Not Available
- TLV: Not Available
NOR-AM Chemical Company
3509 Silverside Rd.
P.O. Box 7495
Wilmington, DE 19803
- Telephone: 302-575-2000
- Emergency : Day: 302-995-8632
- Night: 302-656-5114
References for the information in this PIP can be found in Reference List Number 10
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.