Oil-based pesticide formulations tend to

• A. Evaporate before absorption
• B. Be easily washed off with water
• C. Absorb quickly into the skin
• D. Cause no absorption at all

Answer: (C)

Dermal absorption is strongly influenced by the vehicle carrying the pesticide. Oil-based formulations carry the active ingredient in a lipid-like vehicle that readily mixes with the skin’s own lipids, allowing the pesticide to partition into and move through the outer skin layer more quickly. The oil can also form a thin, occlusive film that keeps the skin hydrated and temporarily increases permeability, further boosting absorption. That’s why oil-based formulations tend to absorb quickly into the skin. They aren’t primarily evaporating away before absorption, nor are they simply washed off by water—the oil film tends to resist rinsing. And there is certainly some absorption, not zero absorption.