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in 1996. EXTOXNET no longer updates this information, but it may be useful
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EXTOXNET primary files maintained and archived at Oregon State
Revised June 1996
Trade and Other Names:
Common names include 4-AP, P-aminopyridine, Gamma-aminopyridine,
Amino-4-pyridine. Trade names include Avitroland and Avitrol 200.
Based on its potential hazard to fish and non-target birds, some
4-aminopyridine formulations are classified by the U.S.
Environmental Protection Agency (EPA) as Restricted Use
Pesticides (RUPs). RUPs may be purchased and used only by
certified applicators. Grain bait formulations of 4-aminopyridine
are in toxicity class III and must bear the signal word CAUTION
and powder concentrate formulations are in toxicity class I and
must bear the signal word DANGER.
4-Aminopyridine, a pyridine compound, is an extremely effective
bird poison. It is one of the most prominent avicides. It is
registered with the EPA for use against red-winged blackbirds,
blackbirds in agricultural fields, grackles, pigeons, and
sparrows around public buildings, and various birds around
livestock feeding pens. Avitrol repels birds by poisoning a few
members of a flock, causing them to become hyperactive. Their
distress calls signal other birds to leave the site. Only a small
number of birds need to be affected to cause alarm in the rest of
the flock. After one alarming exposure, birds will usually not
return to treated areas. Avitrol is available as grain baits or
as a powder concentrate.
Formulation: Avitrol is
available as grain baits or as a powder concentrate.
- Acute toxicity: 4-Aminopyridine is
highly toxic to mammals. The central nervous system is
strongly excited by 4-aminopyridine. Based on
observations with 2-aminopyridine, a similar compound,
individuals with a history of convulsive disorders may be
at an increased risk from exposure to 4-aminopyridine
[30,31]. The principal action of 4-aminopyridine in the
body is to encourage message-carrying (transmitter)
substances to be released throughout the nervous system,
overstimulating it . While intended strictly for use
as a bird repellent, accidental ingestion of as little as
60 mg has caused severe poisoning in adult humans .
It is rapidly absorbed from the gastrointestinal tract
. Poisonings are characterized by thirst, nausea,
dizziness, weakness, and intense sweating, followed by
impairment of normal mental functioning (toxic
psychosis), lack of muscular coordination, tremors,
labored breathing, and generalized seizures .
Symptoms of Avitrol poisoning in rats, dogs, and horses
include over-production of saliva, tendency to become
over-stimulated, and trembling, which can progress to
convulsions. Death can result from respiratory arrest or
heart failure [23,30]. Skin exposure to Avitrol may lead
to systemic intoxication or general overall poisoning
. Avitrol may contribute to the excessive formation
of a substance called methemoglobin. Methemoglobin is
similar to hemoglobin, the oxygen-carrying part of the
blood, except that it cannot carry oxygen. When there is
excess methemoglobin in the blood, oxygen cannot be
transported and blood eventually becomes oxygen depleted,
resulting in the condition methemoglobinemia. The LD50
for 4-aminopyridine is 20 to 29 mg/kg in rats, and is 3.7
mg/kg in dogs [8,167]. It is readily absorbed through the
skin . The dermal LD50 is 326 mg/kg in rabbits
[23,30]. 4-Aminopyridine is an eye irritant. Inflammation
of the iris and conjunctivitis were noted in the eyes of
albino rabbits 1 hour after 10 mg of 4-aminopyridine
hydrochloride were applied. These symptoms disappeared
after 7 days .
- Chronic toxicity: High dietary doses (2
to 3.25 mg/kg/day) caused increased brain weight. Brain
appearance remained normal . However, since dietary
intake is assumed to be negligible, and because
significant repeated exposure is not expected to occur,
EPA has not required long-term toxicity studies of
- Reproductive effects: No data are
- Teratogenic effects: No data are
- Mutagenic effects: No data are currently
- Carcinogenic effects: No data are
- Organ toxicity: Chronic exposure to
4-aminopyridine can cause the breakdown of proper liver
and brain functioning . No effects were found in the
blood and urine of rats and dogs.
- Fate in humans and animals:
4-Aminopyridine is rapidly absorbed into the bloodstream
from the gastrointestinal tract . It is readily broken
down, or metabolized, in the liver into removable
compounds excreted in urine . After intravenous and
oral doses were given to humans, 90.6% and 88.5% was
excreted in the urine . It does not to concentrate
or accumulate in skin. Birds killed with Aritrol are not
poisonous to predators [8,30].
- Effects on birds: 4-Aminopyridine is
highly toxic to birds. The 8-day dietary LC50 is 447 ppm
in Japanese quail, 316 ppm in mourning doves, and 722 ppm
in mallard ducks . Avian reproduction studies
suggest ingestion of sublethal amounts of 4-aminopyridine
is unlikely to cause negative effects on birds'
reproductive systems . There is a large potential for
exposure of non-target, particularly grain-feeding birds.
Migratory birds, finches, and other small seed-feeding
birds may ingest lethal doses that are applied to corn
and sunflower fields.
- Effects on aquatic organisms:
4-Aminopyridine is moderately toxic to warmwater fish.
Fish become increasingly sensitive with increased
exposure . The LC50 ranges from 4 mg/L (in soft
water) to 2.43 mg/L (in hard water) in channel catfish.
The LC50 in is 3.40 mg/L (in soft water) to 3.20 mg/L
(hard water) in bluegill .
- Effects on other organisms: Endangered
species may be adversely affected by 4-aminopyridine
. There is low or nonexistent potential for
secondary poisoning in animals such as cats, dogs, or
birds of prey that may feed upon birds killed by Avitrol
- Breakdown in soil and groundwater:
4-Aminopyridine is readily adsorbed to soil particles and
is highly persistent . It is broken down slowly by
soil microorganisms. It is more likely to remain near the
soil surface where most microbial degradation tends to
occur . The half-life of 4-aminopyridine in soil
with oxygen ranges from 3 months in clay soil to 32
months in sandy-loam soils. The rate at which
4-aminopyridine is metabolized in aerobic soil increases
with greater amounts of organic matter . Studies
indicate that 4-aminopyridine is relatively immobile in
soils. It is not expected to be present in groundwater as
a result of its use on land .
- Breakdown in water: 4-Aminopyridine is
not expected to be present in surface water as a result
of land application of formulated products .
- Breakdown in vegetation: Available plant
metabolism data on sorghum indicate that some breakdown
of 4-aminopyridine does occur, with three breakdown
products; however, no metabolites were found in corn.
4-Aminopyridine is absorbed and moved from one part of a
plant to another to varying degrees, depending on the
manner in which it is applied. Plant uptake of 4-AP is
not expected to be significant in corn and sunflowers
- Appearance: Technical 4-aminopyridine is
a white crystalline solid that contains about 98% active
- Chemical Name: 4-aminopyridine 
- CAS Number: 504-24-5
- Molecular Weight: 94.13
- Water Solubility: Soluble 
- Solubility in Other Solvents: s.s. in
benzene and ether 
- Melting Point: 158 C 
- Vapor Pressure: Not Available
- Partition Coefficient: Not Available
- Adsorption Coefficient: Not Available
- ADI: Not Available
- MCL: Not Available
- RfD: 0.00002 mg/kg/day 
- PEL: Not Available
- HA: Not Available
- TLV: Not Available
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- Phone: 918-622-7763
- Emergency: Not Available
References for the information in this PIP can be found in
Reference List Number 10
information in this profile does not in any way replace or
supersede the information on the pesticide product labeling or
other regulatory requirements. Please refer to the pesticide