Which hazard would require isolating the area with a cordon and controlling ignition sources?

• A. Toxic inhalation hazard
• B. Flammable/ignitable vapor hazard
• C. Corrosive gas hazard
• D. Radioactive plume hazard

Answer: (B)

When a hazard could ignite or explode, the priority is to prevent ignition by keeping people out of the area and removing potential ignition sources. Flammable or ignitable vapors form an explosive atmosphere, and even a small spark, static discharge, hot surface, or open flame can ignite them. Establishing a cordon to isolate the area stops entry and helps ensure ignition sources are controlled or eliminated within the zone, reducing the risk of a fire or explosion.

Other hazards involve different primary controls: toxic inhalation hazards focus on protecting people from inhaling toxic gases through evacuation, sheltering, or PPE; corrosive gas hazards emphasize containment and preventing contact with skin and equipment; radioactive plume hazards center on contamination control and dose management. Ignition source control isn't the primary safety driver for those scenarios, which is why isolating with a cordon and actively managing ignition sources is most appropriate for a flammable/ignitable vapor hazard.