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*	Definitions provided with permission by the Washington State Department of Agriculture with the exception of those with asterisks (*), which are taken from Thurston County's IPM Policy.

A

ABSORPTION

The movement of a chemical into plants, animals (including humans), microorganisms, or soil.

* ACTION LEVEL

The level at which action must be taken to prevent a pest population or vegetation problem at a specific site from reaching the injury level.

ACUTE TOXICITY

The capacity of a pesticide to cause injury from a single exposure. LD50 and LC50 are common indicators of the degree of acute toxicity. (See CHRONIC TOXICITY)

ADHERENCE

The property of a substance to stick to a given surface.

ADJUVANT

A substance added to a pesticide to improve its effectiveness or safety. Same as additive. Examples are penetrants, spreader-stickers, and wetting agents.

ADSORPTION

The process by which chemicals are held or bound to a surface by physical or chemical attraction. Clay and high organic soils tend to adsorb pesticides.

ALGAECIDE (ALGICIDE)

A pesticide used to kill or inhibit algae.

ANNUAL

A plant that completes its life cycle in one year.

ANTICOAGULANT

A chemical that prevents normal blood clotting. The active ingredient in some rodenticides.

AQUIFER

A permeable zone of rock, sand, gravel, or limestone below the earth surface saturated with water.

ATTRACTANT

A substance or device to lure insects or other pests to a trap or poison bait.

B

BACTERIA

Microscopic organisms, some of which are capable of producing diseases in plants and animals.

BACTERICIDE

A chemical used to control bacteria.

BAIT

A food or other substance used to attract a pest to a pesticide or trap where it will be destroyed.

BASAL APPLICATION

Application to plant stems or trunks at or just above ground.

BENEFICIAL INSECT

An insect that is useful or helpful to humans. Examples are pollinators, parasites, and predators of pests.

BIENNIAL

A plant that completes its life cycle in two years.

BIOLOGICAL CONTROL

A pest management strategy that uses predators, parasites, and disease-causing organisms. May be naturally occurring or introduced.

BIOMAGNIFICATION

The process where some organisms accumulate chemical residues in higher concentrates than those found in the organisms they consume.

BRAND NAME

The name, number, or designation of a specific pesticide product or device made by a manufacturer or formulator.

BROADCAST APPLICATION

The uniform application of a pesticide or other material over an entire field or area.

BROADLEAF PLANTS

Plants with broad, rounded, or flattened leaves with netted veins such as dandelions and roses.

BROAD-SPECTRUM PESTICIDE

A pesticide that is effective against a wide range of pests. Usually refers to insecticides and fungicides.

C

CARCINOGENIC

The ability of a substance or agent to induce malignant tumors (cancer).

CARRIER

1) An inert liquid, solid, or gas added to an active ingredient to make a pesticide formulation. 2) The material, usually water or oil, used to dilute the formulated product for application.

CHEMICAL CONTROL

A pest management strategy that involves the use of naturally derived or synthetic chemicals that kill, attract, repel, or otherwise control the growth of pest plants, animals, and microorganisms. Examples are avicides, insecticides, and rodenticides.

CHEMICAL DEGRADATION

The breakdown of a pesticide by processes not involving a living organism.

CHEMICAL NAME

The scientific name of the active ingredient(s) found in the formulated product. This complex name is derived from the chemical structure of the active ingredient.

CHLOROSIS

The yellowing of a plant’s normally green tissue.

CHRONIC TOXICITY

The ability of a material to cause injury from repeated, prolonged exposure to small amounts. (See ACUTE TOXICITY)

COMMERCIAL APPLICATOR

A type of applicator certification or license for an owner or head of a business that commercially applies pesticides on lands of another.

COMMERCIAL CONSULTANT

A type of applicator certification or license for a salesperson who offers technical advice or recommendations to pesticide users.

COMMON NAME

A name given to a pesticides active ingredient by a recognized committee on pesticide nomenclature. Many pesticides are known by a number of trade or brand names, but the active ingredient(s) has only one recognized common name (e.g., the common name for Sevin insecticide is carbaryl).

COMPATIBLE

Chemicals that can be mixed without reducing the effectiveness of any individual chemical.

CONCENTRATION

The amount of active ingredient in a given volume or weight of formulated product.

CONTACT HERBICIDE

A chemical that kills primarily by contact with plant tissue, with little or no translocation.

CONTACT INSECTICIDE

A compound that causes death or injury to insects upon contact. It does not need to be ingested to be toxic to the insect.

CULTURAL CONTROL

A pest management strategy that involves the manipulation of the environment to avert serious pest damage. Examples are crop rotation and pruning.

D

DEFOLIANT

A chemical that initiates the premature drop of leaves.

DEGRADATION

The process by which a chemical compound is broken down to a simpler compound by the action of microorganisms, water, air, sunlight, or other agents. Degradation products are usually, but not always, less toxic than the original compound.

DERMAL TOXICITY

The ability of a pesticide to cause injury to human or animal when absorbed through the skin.

DESICCANT

A chemical that promotes drying or loss of moisture from a leaf or other plant part.

DRIFT

The airborne movement of pesticide spray droplets, dusts, or vapors beyond the intended contact area.

E

ENDANGERED SPECIES

Individual plants or animals with a population that has been reduced to the extent that it is near extinction.

EPA

Environmental Protection Agency. The federal agency responsible for implementing pesticide rules and regulations and registering pesticides.

EPA REGISTRATION NUMBER

A number assigned to a pesticide product by EPA when the product is registered by the manufacturer or the designated agent. The number must appear on all labels for a particular product.

ERADICATION

The complete elimination of a pest from a site.

F

FORMULATION

The pesticide product as purchased, containing a mixture of one or more active ingredients, carriers (inert ingredients), and other additives diluted for safety and ease of application.

FUMIGANT

A pesticide that forms gases that are toxic to plants and animals when absorbed or inhaled.

FUNGICIDE

A chemical used to control fungi.

G

GENERAL USE PESTICIDE

A pesticide that can be purchased and used by the general public. Also called UNCLASSIFIED USE PESTICIDE. (See RESTRICTED USE PESTICIDE)

GERMINATION

The sprouting of a seed or production of a germ tube (mycelium) from a fungus spore.

GRANULE

A dry pesticide formulation. The active ingredient is either mixed with or coated onto an inert carrier to form a small, ready-to-use, low-concentrate particle that does not normally present a drift hazard. Pellets differ from granules only in their precise uniformity, larger size, and shape.

GROUNDWATER

Water sources located beneath the soil surface from which well water is obtained or surface springs are formed.

GROWTH REGULATOR

A chemical that alters the growth processes of a plant or animal.

H

HANDLERS

Employees who handle pesticide products or have high exposure potential. Examples are mixers, applicators, and flaggers, and equipment repair persons.

HAZARD

The potential for injury or degree of danger involved in using a pesticide under a given set of circumstances. Depends on both the toxicity of the pesticide and the chance of exposure to harmful amounts of the chemical.

HERBACEOUS PLANTS

Plants that do not develop woody tissues.

HERBICIDE

A pesticide used to kill or inhibit plant growth.

HOST

A plant or animal on or in which a pest lives.

HYDROLYSIS

Breakdown of a chemical in the presence of water.

I

INERT INGREDIENT

An inactive material in a pesticide formulation that does not have pesticidal activity.

INHALATION

Taking in through the lungs; breathing in.

* INJURY LEVEL

refers to the point in the growth of the pest or vegetation problem at which it will cause some unacceptable level of safety, recreational, public health, ecosystem, aesthetic, or economic injury.

INSECTS

Arthropods characterized by a body composed of three segments and three pairs of legs.

INSECTICIDE

A pesticide used to control or prevent damage caused by insects.

INTEGRATED PEST MANAGEMENT

The use of all suitable pest control methods to keep pest populations below the economic injury level. Methods include cultural practices, use of biological, physical, and genetic control agents, and the selective use of pesticides.

* INTEGRATED PEST MANAGEMENT (IPM)

An approach to pest and vegetation control that utilizes regular monitoring to determine if and when treatments are needed. The approach emphasizes physical, mechanical, cultural, and biological tactics to keep pest numbers or vegetation problems low enough to prevent intolerable damage, annoyance, or public safety hazards. When chemical controls are necessary, they will be the least toxic available and will be used only when no other control methods would be effective or practical.

* IPM PRESCRIPTIONS

Control or eradication plans utilizing the principals of IPM that are specific to types of sites and/or pests and vegetation.

* IPM PROGRAMS

Department-level programs that are developed to implement the Pest and Vegetation Management Policy.

L

LABEL

All printed material attached to or part of a pesticide container.

LARVAE

(plural of LARVA)—The immature form of an insect or other animal that hatches from an egg.

LC50

The concentration of a pesticide, usually in air or water, which can kill 50 percent of a test population of animals. LC50 is usually expressed in parts per million (ppm). The lower the LC50 value, the more acutely toxic the chemical.

LD50

The dose or amount of a pesticide that can kill 50 percent of a test population of animals when eaten or absorbed through the skin. LD50 is expressed in milligrams of chemical per kilogram of body weight of the test animal (mg/kg). The lower the LD50, the more acutely toxic the chemical.

LEACHING

The movement of a substance through soil with water.

M

MECHANICAL CONTROL

A pest management strategy that employs devices to prevent the spread or reduce the infestation of pests, primarily insects, and vertebrate animals. Examples are hand destruction, traps, and fences.

METABOLITE

A compound derived from changes in the active ingredient through chemical, biological, or physical reactions. The metabolite may be simpler, more complex, more poisonous, or less poisonous than the original chemical.

MICROBIAL DEGRADATION

Breakdown of a chemical by microorganisms.

MICROORGANISM

An organism that is so small it cannot be seen without the aid of a microscope.

MODE OF ACTION

The way in which a pesticide exerts a toxic effect on a target plant or animal.

MOLLUSCICIDE

A chemical used to control snails and slugs.

* MONITORING

involves surveying the problem situation in order to understand and identify the extent and location of the problem.

MUTAGENIC

The ability of a substance or agent to cause genetic changes in living cells.

N

NECROSIS

Death of plant or animal tissues resulting in the formation of discolored, sunken, or necrotic (dead) areas.

NEUROTOXIC

The ability of a substance or agent to cause disorders of the nervous system.

NONSELECTIVE PESTICIDE

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.

NONTARGET ORGANISM

Any plant or animal other than the intended target(s) of a pesticide application.

NOXIOUS WEED

A plant defined by law as being particularly troublesome, undesirable, and difficult to control.

O

ORAL TOXICITY

Ability of a pesticide to cause injury when taken by mouth.

ORGANOPHOSPHATES

A large group of pesticides that contain the element phosphorus. Most are nonpersistent insecticides/miticides. Many are highly toxic. Examples are malathion, parathion, and diazinon.

P

PARASITE

A plant, animal, or microorganism living in, on, or with another living organism for the purpose of obtaining all or part of its food.

PATHOGEN

A disease-causing organism.

PERENNIAL

A plant that lives for more than two years.

PERSISTENT PESTICIDE

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.

PEST

An undesirable organism (e.g., insect, fungus, nematode, weed, virus, or rodent) injurious to humans, desirable plants and animals, manufactured products, or natural products.

* PEST

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.

* PESTICIDE

Any substance registered by the Washington State Department of Agriculture as a pesticide.

PESTICIDE

A chemical or other agent used to kill or otherwise control pests, or protect from a pest.

PESTICIDE ACTIVE INGREDIENT

A pesticide active ingredient is the chemical responsible for the killing, suppressing, or repelling action. Thurston County's pesticide review process evaluates an active ingredient’s chemical properties to aid in the identification of pesticide products with the least potential hazard. Thurston County’s IPM Policy identifies which chemical hazards are to be evaluated.

Pesticide active ingredients are required to be listed on the product label, but products may also contain other ingredients not listed on the label. These other ingredients are not supposed to cause any direct killing, suppressing, or repelling action, but they may make a product more effective, aid in application, etc. These other ingredients may also increase or decrease the toxicity (poison hazard) of the product. But, because manufacturers are not required to name the non-active ingredients, Thurston County cannot include them into the pesticide reviews. Therefore, Thurston County does not claim that the active ingredient reviews are reflective of all potential hazards associated with the pesticide products containing them.

PESTICIDE FORMULATIONS

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.

PH

A measure of the acidity/alkalinity of a liquid; acid below pH 7, basic or alkaline above pH 7.

PHEROMONE

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.

PHOTODEGRADATION

Breakdown of chemicals by the action of sunlight.

PHYTOTOXICITY

Injury to plants.

POSTEMERGENCE

After the weed or crop plants have appeared through the soil. Usually used to specify the timing of herbicide applications.

PPE

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 respirators.

PREDATOR

An animal that attacks, feeds on, and kills other animals. Examples are hawks, owls, snakes, fish, and many insects.

PREEMERGENCE

Before weeds or crop plants have appeared through the soil. Used to specify the timing of herbicide applications.

PREMIX

A pesticide product formulated with more than one active ingredient.

PRIVATE APPLICATOR

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 agricultural commodities.

PRIVATE-COMMERCIAL APPLICATOR

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 commodities.

PUBLIC CONSULTANT

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.

PUPA

The intermediate developmental stage of some insects between larva and adult.

R

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.

REGISTERED PESTICIDES

Pesticide products that have been registered by the Environmental Protection Agency for the uses listed on the label.

REPELLENT

A compound that keeps insects, rodents, birds, or other pests away from plants, domestic animals, buildings, or other treated areas.

RESIDUAL PESTICIDE

A pesticide that continues to remain effective on a treated surface or area for an extended period following application.

RESIDUE

A pesticide’s active ingredient or breakdown product(s) that remains in or on a target after treatment.

RESISTANT

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. (See TOLERANT)

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.

RODENTICIDE

A pesticide used to control rodents.

RUNOFF

The movement of water and associated materials on the soil surface.

S

SELECTIVE PESTICIDE

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 other fungi.

SIGNAL WORDS

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 compounds.

SOIL DRENCH

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 depth.

SOIL INJECTION

The placement of a pesticide below the surface of the soil; common application method for fumigants and termiticides.

SOIL STERILANT

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 chemical.

SOLVENT

A liquid such as water, oil, or alcohol that will dissolve another substance (solid, liquid, or gas) to form a solution.

SPOT TREATMENT

Application to small areas.

SPREADER

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.

STICKER

An adjuvant used to improve pesticide spray droplet adherence to a plant, animal, or other treated surface.

STRUCTURAL PESTS

Pests that attack and destroy buildings and other structures, clothing, stored food, and manufactured/processed goods. Examples are termites, cockroaches, clothes moths, rats, and dry-rot fungi.

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.

SUMMER ANNUAL

Plants that germinate in the spring or summer and complete their life cycle within one year.

SURFACTANT

A component of many adjuvants that improves the spreading, dispersing, and/or wetting properties of a pesticide mixture.

SUSCEPTIBLE

1) A plant, animal, or site affected by a pest. 2) Pest populations that can be controlled by pesticides.

SYSTEMIC PESTICIDE

A chemical absorbed and translocated within a plant or animal.

T

TARGET

The plants, animals, structures, areas, or pests at which the pesticide or other control method is directed.

TERATOGENIC

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.

* TIMING

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.

TOLERANCE

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.

TOLERANT

The property of organisms, including pests, to withstand a certain degree of stress, such as pest attack, poor weather, or pesticides.

TOXIC

Poisonous to living organisms.

TOXICITY

The degree or extent that a chemical or substance is poisonous.

TOXIN

A naturally-occurring poison produced by plants, animals, or microorganisms. Examples are the venom produced by black widow spiders and rattlesnakes.

TRANSLOCATION

The movement of materials within a plant or animal from the site of entry. A systemic pesticide is translocated.

V

VAPOR PRESSURE

The property that causes a chemical to evaporate. The higher the vapor pressure, the more volatile the chemical or faster it will evaporate.

VIRUS

Ultramicroscopic parasites composed of proteins. Viruses can only multiply in living tissues and cause many animal and plant diseases.

VOLATILITY, VOLATILIZATION

The change of a substance from a liquid or solid state to a gas at ordinary temperatures when exposed to air.

W

WEED

An unwanted plant.

WETTING AGENT

An adjuvant used to reduce the surface tension between a liquid and contact surface for more thorough coverage.

WINTER ANNUAL

Plants that germinate in the fall and complete their life cycle within one year.

WSDA

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.