Which of the following is an ignition source?

• A. Open flames
• B. Water
• C. Heated surfaces
• D. Paper towels

Answer: (C)

An ignition source is any energy source capable of initiating combustion of a flammable material. A heated surface fits this role because if a surface is hot enough, vapors emitted by a flammable liquid can reach their ignition temperature simply by contacting it. In other words, the heat from the surface provides the energy needed to start the fire without an open flame. Water won’t ignite anything; it cools and can help prevent ignition. Paper towels are combustible and can burn, but they themselves don’t supply ignition energy—they’re fuel that can burn if an ignition source is present. So, a heated surface is a classic ignition source because it can ignite vapors or fuel materials through heat alone.