Which term describes pesticides that move as vapors and can drift?

• A. Stable
• B. Corrosive
• C. Volatile
• D. Soluble

Answer: (C)

Volatility is the tendency of a pesticide to vaporize and move as a gas. When a pesticide is volatile, it readily becomes vapor under normal application temperatures, and those vapors can be carried by air currents away from the target area, causing drift. This is why volatile products pose drift risks and may affect nearby crops, surfaces, or people downwind.

Stable means the substance resists degradation, which is about persistence rather than how it moves through the air. Corrosive describes something that can wear away materials or tissue, not its tendency to volatilize. Soluble refers to dissolving in water, which relates to how the chemical distributes in aqueous environments, not its gas-phase movement. Higher vapor pressure generally indicates greater volatility, leading to more potential for drift.