What general principle helps minimize ignition sources in B28 rooms?

• A. Increase ventilation
• B. Use explosion-proof equipment only
• C. Eliminate or isolate electrical devices, heaters, and open flames within the hazard zone
• D. Keep doors closed

Answer: (C)

In spaces with flammable refrigerants, the top safety rule is to remove any potential ignition sources from the hazard zone. This means eliminating or isolating electrical devices, heaters, and open flames so they cannot operate or cause sparks, heat, or arcs where vapors may be present. If some equipment must stay in place, ensure it is de-energized or physically isolated, and use equipment designed to prevent ignition. Ventilation and keeping doors closed can help manage vapor levels and contain spills, but they don’t replace the need to remove ignition sources—the presence of even a small spark or hot surface could ignite vapors if they’re in the air.