Structural Pest Control Applicator Practice Exam

Which pesticide formulations must be diluted before they are applied?

1. Wettable powders and granules

2. Flowables and some aerosols

3. Wettable powders and emulsifiable concentrates

4. Fumigants and dusts

The correct answer is: Wettable powders and emulsifiable concentrates

The correct answer is that wettable powders and emulsifiable concentrates must be diluted before they are applied. Wettable powders are formulated to be mixed with water to create a suspension that can be sprayed. These powders do not dissolve in water but rather remain as fine particles that must be agitated thoroughly to ensure an even application. By diluting wettable powders with water, the active ingredient can be distributed effectively and evenly over the surface being treated. Emulsifiable concentrates, on the other hand, are designed to form a stable emulsion when mixed with water. Those formulations contain oil-soluble active ingredients and require dilution to ensure proper application and effectiveness. This process allows the pesticide to become a part of the water solution, which can then be easily sprayed onto the target area. In contrast, other formulation types have different application methods. Granules can be applied directly to the ground without needing dilution, and flowables are typically pre-mixed with liquids but may not require further dilution depending on the product's label instructions. Fumigants and dusts are also used without dilution. Fumigants are gaseous pesticides that are usually disseminated in sealed environments, while dusts are applied as dry particles that do not require any mixing with a liquid