The immediate concern with combustible liquid spills is to:

• A. Apply Aqueous Film Forming Foam to the combustible liquid
• B. Prevent ignition
• C. Dike storm drains along collection route
• D. Ignite fuel to allow the combustible materials to burn off

Answer: (B)

The first priority with a spill of a combustible liquid is to prevent ignition. Combustible liquids release vapors that can form flammable mixtures with air, and a nearby ignition source (static, sparks, open flames, hot surfaces, or energized equipment) can ignite those vapors quickly, causing a fire or explosion. So the immediate action is to remove ignition sources, steadying the area by grounding and bonding containers, shutting off potential ignition sources, and isolating people from the spill. Containing the spill to limit environmental spread—such as stopping flow and preventing it from reaching drains—also matters, but it takes a secondary role to stopping ignition. Deliberately igniting the fuel to burn off or applying foam to a non-fire spill aren’t appropriate immediate actions; they introduce additional risks or are only relevant if a fire is already present. By keeping ignition sources controlled, you reduce the most dangerous outcome and buy time to implement proper containment and cleanup.