What must be shut off before initiating a ULV pesticide treatment?

In a ULV (Ultra-Low Volume) pesticide treatment, it is crucial to ensure safety and prevent accidents, particularly in relation to potential ignition sources. Shutting off electrical equipment and open flame sources is essential because ULV treatments often involve the application of pesticides in a fine aerosol or mist. Any spark from electrical equipment could ignite the pesticide mist, creating a dangerous situation.

Furthermore, open flames pose an obvious fire hazard during pesticide application. By eliminating these potential ignition sources, the risk of fire or explosion is significantly reduced, ensuring a safer environment for both the applicator and the surrounding area.

The other options, while they relate to safety, do not address the specific hazards associated with ULV treatments as directly. For example, while it is generally good practice to close windows and shutter systems to minimize drift, it is the electrical equipment and open flames that present the most immediate danger during the application process.