Identify two ignition risks in a structure fire and one mitigation measure for each.

• A. Gas leaks or gas line ruptures (isolate and shut off gas; ventilate); Electrical equipment (de-energize and isolate; maintain distance)
• B. Gas leaks only
• C. Electrical equipment only
• D. Structural steel failure

Answer: (A)

Ignition risk management in a structure fire comes from both fuel sources and energy sources that can ignite fuel vapors or dust. The two common ignition risks are gas leaks or ruptured gas lines and electrical equipment.

For gas leaks or ruptures, the danger is a flammable gas-air mixture that can ignite from a spark, flame, or hot surface. The best mitigation is to isolate and shut off the gas to stop the fuel source, and then ventilate to disperse any accumulated gas so it isn’t concentrated near ignition sources.

For electrical equipment, energized components can produce sparks or arcing that can ignite vapors or dust. The mitigation is to de-energize and isolate the electrical equipment, removing the ignition source, and maintain a safe distance to reduce exposure to any residual heat or activity around those components.

Other options miss one of these key ignition sources or point to a non-ignition hazard, like structural steel failure, which isn’t an ignition risk in itself.