*Definition provided with permission by the Washington State Department of Agriculture.
Death of plant or animal tissues resulting
in the formation of discolored, sunken, or
necrotic (dead) areas.
The ability of a substance or agent to cause
disorders of the nervous system.
A pesticide that is toxic to a wide range of
plants or animals without regard to species. For
example, a nonselective herbicide can kill or
damage all plants it contacts.
Any plant or animal other than the intended
target(s) of a pesticide application.
A plant defined by law as being particularly
troublesome, undesirable, and difficult to
Ability of a pesticide to cause injury when
taken by mouth.
A large group of pesticides that contain the
element phosphorus. Most are nonpersistent insecticides/miticides.
Many are highly toxic. Examples are malathion, parathion,
A plant, animal, or microorganism living in,
on, or with another living organism for the
purpose of obtaining all or part of its food.
A disease-causing organism.
A plant that lives for more than two years.
A pesticide chemical (or its metabolites)
that remains active in the environment more than
one growing season. These compounds sometimes
accumulate in animal and plant tissues. Examples
are DDT, chlordane, and dieldrin.
An undesirable organism (e.g., insect,
fungus, nematode, weed, virus, or rodent)
injurious to humans, desirable plants and
animals, manufactured products, or natural
Any insect, rodent, nematode, snail, slug,
weed and any form of plant or animal life or
virus, except virus on or in a living person or
other animal, that adversely interferes with the
aesthetic, health, environmental, or economic
goals of humans.
Any substance registered by the Washington
State Department of Agriculture as a pesticide.
A chemical or other agent used to kill or
otherwise control pests, or protect from a pest.
Mixtures of active and inert ingredients.
Make an active ingredient more convenient to
handle; safer, easier, and more accurate to
apply; and in some cases more attractive to the
pest. Examples are emulsifiable concentrates,
water-dispersible granules, and fumigants.
A measure of the acidity/alkalinity of a
liquid; acid below pH 7, basic or alkaline above
A substance emitted by an animal to
influence the behavior of other animals of the
same species. Some are synthetically produced
for use in insect traps.
Breakdown of chemicals by the action of
Injury to plants.
After the weed or crop plants have appeared
through the soil. Usually used to specify the
timing of herbicide applications.
Personal protective clothing and equipment.
Intended to protect a person from exposure
during the handling and application of
pesticides. Includes long-sleeved shirts, long
trousers, coveralls, hats, gloves, shoes, and
An animal that attacks, feeds on, and kills
other animals. Examples are hawks, owls, snakes,
fish, and many insects.
Before weeds or crop plants have appeared
through the soil. Used to specify the timing of
A pesticide product formulated with more
than one active ingredient.
A type of applicator certification or
license for a land owner/lessee or employee who
uses restricted use pesticides on cropland or
associated agricultural non-cropland to produce
A type of applicator certification or
license for a land owner/lessee or their
employee who uses restricted use pesticides for
purposes other than producing agricultural
A type of certification or license for a
government agency or utility company employee
who offers technical advice or recommendations
for pesticide use (other than for home or
gardens) during the course of their employment.
The intermediate developmental stage of some
insects between larva and adult.
RATE OF APPLICATION
The amount of pesticide applied to a plant,
animal, unit area, or surface; usually measured
as per acre, per 1,000 square feet, per linear
feet, or per cubic feet.
Pesticide products that have been registered
by the Environmental Protection Agency for the
uses listed on the label.
A compound that keeps insects, rodents,
birds, or other pests away from plants, domestic
animals, buildings, or other treated areas.
A pesticide that continues to remain
effective on a treated surface or area for an
extended period following application.
A pesticide’s active ingredient or breakdown
product(s) that remains in or on a target after
—1) A population of organisms that are uninjured
or unaffected by a certain dosage of pesticide chemical
used to control other populations of the same organism successfully.
2) Plants and animals that are unaffected by a pest species.
RESTRICTED USE PESTICIDE
A pesticide that can be purchased only by
certified pesticide applicators and used only by
certified applicators or persons directly under
their supervision. Not available for use by the
general public because of their high toxicities
and/or environmental hazards.
A pesticide used to control rodents.
The movement of water and associated
materials on the soil surface.
A pesticide that is toxic to some pests, but
has little or no effect on other similar
species. Some fungicides are so selective that
they control only water-mold pathogens and no
Required word(s) that appear on pesticide
labels to denote the relative toxicity of the
product: DANGER-POISON used with a skull and
crossbones symbol for highly toxic compounds,
DANGER for skin and eye irritants, WARNING for
moderately toxic, and CAUTION for slightly toxic
To soak or wet the ground surface with a
pesticide. Large volumes of a pesticide mixture
are usually needed to saturate the soil to any
The placement of a pesticide below the
surface of the soil; common application method
for fumigants and termiticides.
A chemical or agent that prevents the growth
of all organisms present in the soil; a
nonselective pesticide. Soil sterilization may
be temporary or permanent depending on the
A liquid such as water, oil, or alcohol that
will dissolve another substance (solid, liquid,
or gas) to form a solution.
Application to small areas.
An adjuvant used to enhance the spread of a
pesticide over a treated surface, thus
increasing the area that a given volume of
liquid will cover.
An adjuvant used to improve pesticide spray
droplet adherence to a plant, animal, or other
Pests that attack and destroy buildings and
other structures, clothing, stored food, and
manufactured/processed goods. Examples are
termites, cockroaches, clothes moths, rats, and
STRUCTURAL PEST INSPECTOR
A type of applicator certification or
license for an individual who inspects a
structure for wood-destroying organisms or
conditions conducive to their development.
Plants that germinate in the spring or
summer and complete their life cycle within one
A component of many adjuvants that improves the
spreading, dispersing, and/or wetting properties of a pesticide
1) A plant, animal, or site affected by a
pest. 2) Pest populations that can be controlled
A chemical absorbed and translocated
within a plant or animal.
The plants, animals, structures, areas, or
pests at which the pesticide or other control
method is directed.
The property of a substance or agent able to
produce abnormalities or defects in living human
or animal embryos and fetuses. These defects are
not usually inheritable.
involves applying a treatment action during the
most vulnerable time in the life cycle of the pest or vegetation
with the least impact on natural enemies.
A regulation that establishes the maximum
amount of pesticide residue (active ingredient
or certain metabolites) that may legally remain
in or on a raw agricultural commodity (food or
feed product) at harvest or slaughter.
The property of organisms, including pests,
to withstand a certain degree of stress, such as
pest attack, poor weather, or pesticides.
Poisonous to living organisms.
The degree or extent that a chemical or
substance is poisonous.
A naturally-occurring poison produced by
plants, animals, or microorganisms. Examples are
the venom produced by black widow spiders and
The movement of materials within a plant or
animal from the site of entry. A systemic
pesticide is translocated.
The property that causes a chemical to evaporate.
The higher the vapor pressure, the more volatile the chemical
or faster it will evaporate.
Ultramicroscopic parasites composed of
proteins. Viruses can only multiply in living
tissues and cause many animal and plant
The change of a substance from a liquid or
solid state to a gas at ordinary temperatures
when exposed to air.
An unwanted plant.
An adjuvant used to reduce the surface
tension between a liquid and contact surface for
more thorough coverage.
Plants that germinate in the fall and
complete their life cycle within one year.
Washington State Department of Agriculture.
A regulatory agency that administers the
Washington Pesticide Application Act of 1961 and
the Washington Pesticide Control Act of 1971.