WASHINGTON PESTICIDE LAWS AND SAFETY STANDARD
EXAM SHEET 2025/2026 QUESTIONS AND ANSWERS
GRADED A+
✔✔Nonselective Herbicides - ✔✔Herbicides that kill/control most or all plants.
✔✔Pre-Emergence Treatment - ✔✔A treatment made prior to emergence of a crop or
weed.
✔✔Post-Emergence Treatment - ✔✔Any treatment made after emergence of a
specified crop or weed.
✔✔GPA - ✔✔5940 x nozzle output GPM/ MPH x nozzle spacing inches
✔✔Amount ai - ✔✔Amount Product x % ai
✔✔Amount Product - ✔✔Amount ai / % ai
✔✔lbs ai - ✔✔Gal Product x lb ai/gal
✔✔Gal Product - ✔✔lbs ai / lb ai per gallon
✔✔Emulsifiable Concentrates - ✔✔Are liquid formulations with the active ingredient
dissolved in one or more petroleum solvents. Relatively easy to handle and versatile,
but may have high phytotoxicity hazard (plant injury).
✔✔Emulsion - ✔✔When oil droplets suspend in water (active ingredient formulation +
water)
✔✔Solutions - ✔✔Are formulations with a water soluble active ingredient dissolved in
one or more liquids.
✔✔Soluble Powders - ✔✔Are dry, powdered formulations containing 25-80% active
ingredient that readily dissolves in water. They are cost effective offering lower
phytotoxicity, but powder may be dangerous if inhaled.
✔✔Wettable Powders (WP) - ✔✔Are dry, finely ground formulations containing 25-80%
active ingredient but unlike soluble powders, they do not dissolve in water. The active
ingredient is combined with inert carrier (clay/talc) and mixed with an emulsifier.
✔✔Flowables - ✔✔Are finely ground solid particles combined with active ingredient and
suspended in a liquid carrier. Similar to a wettable powder, except it is formulated as a
liquid suspension.
, ✔✔Invert Emulsions - ✔✔Contain water-soluble pesticides dispersed in oil carriers.
They require a special emulsifier that allows the pesticide to be mixed with large
volumes of petroleum based carriers like fuel oil.
✔✔Water Dispersible Granules - ✔✔A granular form of pesticides that is dustless and
breaks apart in liquid.
✔✔Dusts - ✔✔Formulations contain a low % of active ingredient (0.5-10%), plus a finely
ground inert substance such as talc, clay, nut hulls, or volcanic ash. These are always
used dry.
✔✔Granules and Pellets - ✔✔Dry, ready-to-use materials usually containing from 2-
15% active ingredient. Most granules are prepared by applying the active ingredient as
a liquid to a coarse, porous, solid material such as clay or ground corn cobs. These are
often used to control soil-borne pests.
✔✔Baits - ✔✔This formulation has an active ingredient mixed with an edible substance
or some other attractant. Typically less than 5% active ingredient and attracts pests like
animals, insects, rodents, etc.
✔✔Aerosols - ✔✔Contain no active ingredient in solution (usually a petroleum distillate)
and packaged in a pressurized container.
✔✔Fumigants - ✔✔Are pesticides that are active as gases. These are often formulated
as liquids, either as volatile liquids or under pressure to become gases when released.
Others are solids that release gases under conditions of high humidity. (MOST
HAZARDOUS OF ALL PESTICIDES!)
✔✔Adjuvant - ✔✔A chemical added to a pesticide formulation or mixture to improve its
performance and safety.
✔✔Surfactant - ✔✔Are "surface active ingredients" and alter the dispersing, spreading,
and/or wetting properties of spray droplets.
✔✔Danger-Poison Peligro - ✔✔These words (along with skull and crossbones) appear
on all products that are highly toxic by any route of entry in the body. "Poison" indicates
the product can cause death at low rates.
✔✔Danger Peligro - ✔✔Products with this signal word can cause very severe eye
damage or skin irritation. These products are NOT lethal at low dosages.
✔✔Warning Aviso - ✔✔This word signals that the product is moderately toxic orally,
dermally, or through inhalation, or causes moderate skin/eye irritation.
EXAM SHEET 2025/2026 QUESTIONS AND ANSWERS
GRADED A+
✔✔Nonselective Herbicides - ✔✔Herbicides that kill/control most or all plants.
✔✔Pre-Emergence Treatment - ✔✔A treatment made prior to emergence of a crop or
weed.
✔✔Post-Emergence Treatment - ✔✔Any treatment made after emergence of a
specified crop or weed.
✔✔GPA - ✔✔5940 x nozzle output GPM/ MPH x nozzle spacing inches
✔✔Amount ai - ✔✔Amount Product x % ai
✔✔Amount Product - ✔✔Amount ai / % ai
✔✔lbs ai - ✔✔Gal Product x lb ai/gal
✔✔Gal Product - ✔✔lbs ai / lb ai per gallon
✔✔Emulsifiable Concentrates - ✔✔Are liquid formulations with the active ingredient
dissolved in one or more petroleum solvents. Relatively easy to handle and versatile,
but may have high phytotoxicity hazard (plant injury).
✔✔Emulsion - ✔✔When oil droplets suspend in water (active ingredient formulation +
water)
✔✔Solutions - ✔✔Are formulations with a water soluble active ingredient dissolved in
one or more liquids.
✔✔Soluble Powders - ✔✔Are dry, powdered formulations containing 25-80% active
ingredient that readily dissolves in water. They are cost effective offering lower
phytotoxicity, but powder may be dangerous if inhaled.
✔✔Wettable Powders (WP) - ✔✔Are dry, finely ground formulations containing 25-80%
active ingredient but unlike soluble powders, they do not dissolve in water. The active
ingredient is combined with inert carrier (clay/talc) and mixed with an emulsifier.
✔✔Flowables - ✔✔Are finely ground solid particles combined with active ingredient and
suspended in a liquid carrier. Similar to a wettable powder, except it is formulated as a
liquid suspension.
, ✔✔Invert Emulsions - ✔✔Contain water-soluble pesticides dispersed in oil carriers.
They require a special emulsifier that allows the pesticide to be mixed with large
volumes of petroleum based carriers like fuel oil.
✔✔Water Dispersible Granules - ✔✔A granular form of pesticides that is dustless and
breaks apart in liquid.
✔✔Dusts - ✔✔Formulations contain a low % of active ingredient (0.5-10%), plus a finely
ground inert substance such as talc, clay, nut hulls, or volcanic ash. These are always
used dry.
✔✔Granules and Pellets - ✔✔Dry, ready-to-use materials usually containing from 2-
15% active ingredient. Most granules are prepared by applying the active ingredient as
a liquid to a coarse, porous, solid material such as clay or ground corn cobs. These are
often used to control soil-borne pests.
✔✔Baits - ✔✔This formulation has an active ingredient mixed with an edible substance
or some other attractant. Typically less than 5% active ingredient and attracts pests like
animals, insects, rodents, etc.
✔✔Aerosols - ✔✔Contain no active ingredient in solution (usually a petroleum distillate)
and packaged in a pressurized container.
✔✔Fumigants - ✔✔Are pesticides that are active as gases. These are often formulated
as liquids, either as volatile liquids or under pressure to become gases when released.
Others are solids that release gases under conditions of high humidity. (MOST
HAZARDOUS OF ALL PESTICIDES!)
✔✔Adjuvant - ✔✔A chemical added to a pesticide formulation or mixture to improve its
performance and safety.
✔✔Surfactant - ✔✔Are "surface active ingredients" and alter the dispersing, spreading,
and/or wetting properties of spray droplets.
✔✔Danger-Poison Peligro - ✔✔These words (along with skull and crossbones) appear
on all products that are highly toxic by any route of entry in the body. "Poison" indicates
the product can cause death at low rates.
✔✔Danger Peligro - ✔✔Products with this signal word can cause very severe eye
damage or skin irritation. These products are NOT lethal at low dosages.
✔✔Warning Aviso - ✔✔This word signals that the product is moderately toxic orally,
dermally, or through inhalation, or causes moderate skin/eye irritation.
