Fire Point Definition
Fire point is the lowest temperature where the vapor of a liquid will initiate and sustain a combustion reaction. By definition, the fuel must continue to burn for at least 5 seconds following ignition by an open flame for the temperature to be considered the fire point.
Fire Point vs Flash Point
Contrast this with the flash point, which is a lower temperature at which a substance will ignite, but may not continue to burn.
The fire point for a specific fuel is not typically listed, while flash point tables are readily available. Generally, the fire point is about 10 °C higher than the flash point, but if the value must be known, it should be determined experimentally.