To prevent vapor hazards in greenhouse applications, which humidity approach is recommended?

• A. Maintain high humidity to keep droplets in suspension.
• B. Use dry air only and avoid humidity monitoring.
• C. Avoid high humidity; maintain lower humidity.
• D. Run humidifiers at maximum during application.

Answer: (C)

Humidity levels influence how pesticide vapors behave in a greenhouse. When the air is too humid, some components can volatilize more readily or linger in the breathing zone, increasing the risk of vapor exposure for the applicator. Keeping relative humidity lower helps limit this vapor formation and accumulation, reducing the potential inhalation hazard during application. The idea is to avoid conditions that encourage vapor release and buildup. The other approaches would either promote more vapor exposure or neglect the humidity factor altogether: trying to keep droplets suspended with high humidity can still keep vapors around longer, relying on dry air without humidity monitoring ignores a key safety variable, and maximizing humidification during application would likely raise vapor levels rather than lower them.