What defines ignition temperature?

Ignition temperature is specifically defined as the minimum temperature required for a substance to ignite and begin combustion. This temperature is crucial in fire investigations as it establishes the threshold at which a material will start to react with oxygen and produce heat, light, and possibly flame. Understanding ignition temperature helps investigators assess fire scenarios, determine potential ignition sources, and identify materials that may have contributed to the spread of fire.

The other definitions provided do not accurately represent the concept of ignition temperature. For instance, the highest temperature at which a substance burns does not capture the essence of the ignition point. Similarly, the temperature at which a substance melts is unrelated to its ignition characteristics, and the temperature needed for combustion to be self-sustaining refers to the conditions necessary for maintaining a fire, not the onset of ignition itself. Therefore, the correct characterization of ignition temperature is critical for effective fire analysis and investigation.