The greatest pesticide exposure hazard to an applicator occurs during which activity?

• A. Mixing and loading of concentrates
• B. Changing sprayer nozzles
• C. Sprayer calibration
• D. Rinsing the sprayer after an application

Answer: (A)

During mixing and loading, you are handling the product in its concentrated form and transferring it into the spray tank. This puts skin, eyes, and lungs at the highest risk because any splash, spill, or aerosol exposure occurs before the chemical has been diluted. The concentration is at its peak, so even small leaks or drips can deliver a large dose in a short time. The act of pouring, measuring, and opening containers often involves close contact with the concentrated pesticide, and protective practices can be harder to maintain consistently in this moment, increasing the chance of dermal or inhalation exposure.

In contrast, the other tasks involve working with a diluted or contained solution. Changing nozzles and calibrating the sprayer generally deal with spray solution inside the system or in the tank, where the pesticide is already diluted by water, reducing potential exposure. Rinsing the sprayer after application also uses diluted residues and rinse water, which lowers the concentration the operator encounters. So while these activities still require caution, they typically do not pose as much exposure risk as mixing and loading the concentrate.