A Class B fire is most often ignited by sparks, open flames, or hot surfaces coming into contact with flammable liquids or gases.

Quick Scoop

  • Typical ignition sources for a Class B fire include:
    • Open flames (matches, lighters, pilot lights, welding or cutting torches).
* Electrical sparks (faulty wiring, switches, motors, static discharge).

* Hot surfaces (overheated machinery, engines, heaters, lighting fixtures).
  • These sources ignite vapors from fuels like gasoline, solvents, oils, alcohols, and flammable gases, not the liquid surface itself.

Common ignition source examples

  • Lighting a cigarette or using a lighter near gasoline or solvent fumes.
  • Switching on a power tool or machine that throws a small electrical spark in an area with flammable vapors.
  • A hot engine, heater, or lamp in a poorly ventilated area with fuel or solvent vapors present.

In short, any flame, spark, or sufficiently hot object in the presence of flammable liquid or gas vapors is an ignition source associated with a Class B fire.

Information gathered from public forums or data available on the internet and portrayed here.