Which of the following pesticide formulations is least readily absorbed through the skin?

The choice of wettable powders as the formulation least readily absorbed through the skin is supported by their specific characteristics. Wettable powders are typically finely ground solids that are mixed with water to form a suspension. Because they are powdered and not liquid, they have lower levels of dermal absorption compared to liquid formulations.

Moreover, wettable powders tend to adhere less directly to the skin as they do not contain the solvents or emulsifiers that enhance skin penetration, unlike emulsifiable concentrates or solvent-based liquids. These other formulations can dissolve or solubilize more easily, allowing active ingredients to penetrate through the skin more effectively. Dust formulations, while also having lower skin absorption than liquid formulations, can still be inhaled or settle on the skin, leading to potential exposure. In summary, wettable powders' solid nature and lower dermal absorption capacity make them the formulation with the least propensity for skin absorption among the provided options.