Under what conditions is it appropriate to use a pesticide with high volatility in terms of risk?

• A. Only if label permits and weather is calm, regardless of wind or drift.
• B. Only if label permits and under appropriate weather conditions; avoid drift or high vapor pressure.
• C. It's always appropriate to use high-volatility pesticides on any day.
• D. It should always be avoided, regardless of label.

Answer: (B)

Pesticides with high volatility carry more risk of moving off-target through vapor drift and rapid evaporation. The way to manage that risk is to follow two essential conditions: the product label must allow use of that formulation, and the weather must be suitable to minimize drift and volatilization. When the label permits and conditions are favorable—typically calm, stable air with no strong winds, and temperatures that don’t aggressively drive evaporation—the risk of off-target movement is reduced. High vapor pressure means the product tends to vaporize quickly, increasing the chance of inhalation exposure and drift, so avoiding days or times when vapor pressure would be high is important. In short, you should use a high-volatility pesticide only under label-approved circumstances and during weather that minimizes drift and volatilization.