Abrasive: Capable of wearing away or grinding down another object.

Active ingredients (a.i.): The chemicals in a pesticide product that controls the target pest.

Acute effects: Illnesses or injuries that may appear immediately after exposure to a pesticide (usually within 24 hours).

Adjuvant: Chemical added to a pesticide formulation or tank mix to increase its effectiveness or safety.

Agitate: To stir or mix.

Alkaline: The opposite of acidic; having a pH greater than 7.

Allergic effects: Harmful effects, such as skin rash o r asthma, that some people develop in reaction to pesticides that do not cause the same reaction in most other people.

Back-siphoning: The movement of liquid pesticide mixture back through the filling hose and into the water source.

Carrier: The primary material used to allow a pesticide to be dispersed effectively; for example, the talc in a dust formulation, the water mixed with a wettable powder before a spray application, or the air that disperses the pesticide in an air blast application.

Catch basin: A tub or tray in which a pesticide container is placed during mixing. The use of a catch basin helps recover spilled pesticides, washwater, or rinsate. Basically it is a container within a container.

Chemical-resistant: Able to prevent movement of the pesticide through the material during the period of use.

Chronic effects: Illnesses or injuries that do not appear immediately (within 24 hours) after exposure to a pesticide or combination of pesticides.

Collecting pad or tray: A safety system designed to contain and recover spills, rinsates, leaks, and other pesticide-containing substances.

Concentrated: Having a high percentage of active ingredient.

Concentrates: Pesticides that have a high percentage of active ingredient.

Decontaminate: Remove pesticide from surfaces or organisms that are exposed so no further harm or damage can occur.

Delayed effects: Illnesses or injuries that do not appear immediately (within 24 hours) after exposure to a pesticide or combination of pesticides.

Diluent: Anything used to dilute a pesticide. Water, for example, is a diluent. Not to be confused with carrier.

Dilute: To make less concentrated.

Distributor products: Products that are produced and registered by a manufacturer or formulator and sold under a different name by a distributor.

Drift: Pesticide movement away from the release site in the air.

Ecosystem: A system formed by the interaction of a community of organisms with their environment.

Emulsifier: Chemical that allows petroleum-based pesticides like emulsifiable concentrates (EC's) to mix with water.

Emulsion: A mixture of two or more liquids that are not soluble in one another. One is suspended as small droplets in the other.

Endangered species: Organisms whose survival as a species has been designated by a Federal agency to be endangered or threatened.

Exposure: Coming into contact with a pesticide; getting a pesticide on a surface or in or on an organism.

Eyewash dispenser: Commercially available system for flushing contaminants out of the eyes.

Formulation: Pesticide product as sold, usually a mixture of active and inert ingredients.

Fumigant: Pesticide that is a vapor or gas or that forms a vapor or gas when applied and whose pesticidal action occurs in the gaseous state.

Ground water: Water beneath the earth's surface in soil or rock.

Heat stress: Illness that occurs when the body is subjected to more heat than it can cope with.

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

Inert ingredients: Inactive components of a pesticide formulation that are used to dilute the pesticide or to make it safer, more effective, easier to measure, mix, and apply, and more convenient to handle.

Insoluble: Does not dissolve in liquid.

Juvenile hormones: Natural insect chemicals that keep the earlier stages of an insect from changing into the normal adult form.

Labeling: The pesticide product label and other accompanying materials that contain directions which pesticide users are legally required to follow.

Leaching: The movement of pesticide in water or another liquid downward through soil or other planting medium.

Liability: Legal responsibility.

Mycoplasmas: The smallest known living organisms that can reproduce and exist apart from other living organisms. They obtain their food from plants.

MSHA: Mine Safety and Health Administration.

Nematodes: Small, usually microscopic, eel-like roundworms.

NIOSH: National Institute for Occupational Safety and Health.

Non-cropland: Areas which will not in the foreseeable future be used to grow food, feed, or fiber crops, or to pasture animals.  Examples of non-crop land include railroad beds, lumberyards, highway shoulders, etc. This could include areas in a residential setting. Driveways, roadsides, vacant lots, and weed control around a ranchette are examples.

Nonporous surfaces: Surfaces that have no openings to allow liquid to be absorbed or pass through.

Nontarget organism: Any plant or animal other than the pest that is being controlled.

Nontarget: Any site or organism other than the site or pest toward which the control measures are being directed.

Offsite: Outside the area where the pesticide is being released.

Oncogenicity: The ability to cause tumors.

Organic matter: Materials and debris that originated as living plants or animals.

OSHA: Occupational Safety and Health Administration in the United States Department of Labor.

Parasite: An organism living on, in, or with another living organism for the purpose of obtaining food.

Pasture: Land on which the foliage is grazed by animal stock, and on which agricultural practices are performed on an annual or more frequent basis. Any fence encompassing a pasture is included as part of the pasture. "Agricultural practices" include, but are not limited to, cultivation, seeding, fertilization, irrigation, and pesticide application.

Pathogen: An organism that causes disease in other organisms.

Penetrant: Chemical that helps a pesticide active ingredient to get through a surface and into an object or organism.

Personal protective equipment (PPE): Devices and clothing worn to protect the human body from contact with pesticides or pesticide residues.

Pesticide handler: A person who directly works with pesticides, such as during mixing, loading, transporting, storing, disposing, and applying, or working on pesticide equipment.

Pesticide handling: Directly working with pesticides, such as during mixing, transporting, storing, disposing, and applying, or working on pesticide equipment.

Petroleum-based: Made from petroleum products. Examples are: xylene, refined oil, and kerosene.

Pheromones: Chemicals emitted by an organism to influence the behavior of other organisms of the same species.

Physically Present: The "physically present" language on a pesticide label requires a certified applicator to provide "direct supervision" and to be "physically present" when noncertified persons are involved in applying, mixing, and loading these pesticides and when repairing and cleaning the application equipment. The "physically present" statement means the certified applicator must be in-line of sight to observe that noncertified persons are following the label directions, to provide guidance if the label is unclear, and to affect changes in procedures if they are not being adhered to or unusual situations occur.

Porous surfaces: Surfaces that have tiny openings which allow liquid to be absorbed or to pass through.

Precautionary statement: Pesticide labeling statement that alerts you to possible hazards from use of the pesticide product and that may indicate specific ways to avoid the hazards.

Predator: An organism that attacks, kills, and feeds on other organisms.

Rangeland: Land on which the foliage is grazed by animal stock, but on which agricultural practices are not performed on a annual or more frequent basis.

Release: When a pesticide leaves its container or the equipment or system containing it and enters the environment. Release can be intentional, as in an application, or by accident, as in a spill or leak.

Residue: The part of a pesticide that remains in the environment for a period of time following application or a spill.

Rinsate: Pesticide-containing water (or another liquid) that results from rinsing a pesticide container, pesticide equipment, or other pesticide-containing materials.

Runoff: The movement of pesticide away from the release site in water or another liquid flowing horizontally across the surface.

Scouting: Regularly searching for, identifying, and assessing numbers of pests and the damage they are causing.

Sensitive areas: Sites or organisms that are particularly vulnerable to harmful effects from pesticides.

Sensitive: Particularly vulnerable to harm from pesticide exposure.

Soluble: Able to be dissolved in another substance, usually a liquid.

Solvent: A liquid, such as water, kerosene, xylene, or alcohol, that will dissolve a pesticide (or other substance) to form a solution.

Surface water: Water on top of the earth's surface, such as in lakes, streams, rivers, irrigation ditches, or storm water drains.

Surfactant: Surface Acting Agent - Material that can greatly reduce the surface tension of water when used in very low concentrations. Soap is a simple surfactant. Pesticide surfactants are nonionic (do not ionize, but will have a slight electrostatic charge due to the polarity of dissimilar atoms in the molecule), anionic (ionized, have a strong negative charge), or cationic (ionized, have a strong positive charge).

Suspension: A substance that contains undissolved particles mixed throughout a liquid.

Systemic pesticide: Pesticide that is absorbed and circulated by a plant or animal so that the plant or animal is toxic to pests that feed on it.

Target pest: The pest toward which control measures are being directed.

Target site: The site toward which control measures are being directed.

Target: The site or pest toward which control measures are being directed.

Tip-and-pour: Built-in measuring device that fills with a given amount of pesticide when the container is tilted.

Toxicity: Measure of a pesticide's ability to cause acute, delayed or allergic effects.

Use site: The immediate environment where a pesticide is being mixed, loaded, applied, transported, stored, or disposed of, or where pesticide-contaminated equipment is being cleaned.

Volatile: Evaporating rapidly; turning easily into a gas or vapor.

Water-based pesticides: Pesticides that use water as the only diluent or carrier.

Worker Protection Standard: All pesticides labeled for use in agricultural production sites are required to comply with Worker Protection Standard (WPS) labeling requirements which include personal protective equipment (PPE), restricted entry intervals (REI), and other worker safety requirements. Generally, these requirements are located in a distinct section of the label and specify that they apply to agricultural production operations. When a dual-use pesticide is being used in a non-agricultural production site, the WPS requirements do not apply. If the rest of the label is silent regarding PPE, REI, or other safety issues, then no label requirement applies.