What should be done before using portable machines to clean areas not reached by fixed machines?

Before using portable machines to clean areas not reached by fixed machines, it's essential to ventilate the tank to eliminate any electrostatically charged mist because this action directly addresses potential hazards that could arise during the cleaning process.

Electrostatic discharges can lead to sparks, which pose a significant risk of fire or explosion, especially in environments that contain flammable vapors or residues. Proper ventilation helps to dissipate any electrostatic charge that may have built up in the atmosphere, creating a safer working environment. By ensuring that the air inside the tank is replaced with fresh, non-flammable air, the risks associated with electrostatic sparks are minimized, thereby promoting safety for the personnel operating portable machines.

Other procedures, while important in various situations, do not specifically target the same electrostatic risks. For instance, evacuating personnel or draining the tank might be necessary under certain conditions, but they don't address the immediate concern of electrostatic charge as effectively as ventilation does. Sealing the tank could aggravate the buildup of flammable vapors instead of alleviating it. Thus, prioritizing ventilation is a critical safety measure before engaging in cleanup operations with portable equipment.