Structural Pest Control Applicator Practice Exam

What type of formulation typically has more visible residue after application?

1. Aerosol

2. Wettable powder

3. Emulsifiable concentrate

4. Granular

The correct answer is: Wettable powder

Wettable powders are known for their tendency to leave visible residues after application. This is primarily due to their formulation, which consists of a finely ground powder that needs to be mixed with water to create a suspension for application. When applied, some of this powder does not completely dissolve or integrate into the solution, resulting in visible particles that may settle or adhere to surfaces. The physical properties of wettable powders contribute to this visibility. Unlike other formulations such as aerosols or emulsifiable concentrates that may evaporate or disperse more completely, wettable powders may remain on the surfaces of treated areas, especially if applied in heavier concentrations or under certain environmental conditions. Granular formulations do leave visible residues as well, but they are typically used in specific contexts such as soil applications and often blend into the environment without being as prominently visible on surfaces compared to wettable powders.