Fire Point

Fire point could be said to be the lowest temperature at which a volatile liquid, after its vapors have been ignited, will give off vapors at a rate sufficient to sustain combustion.

It can also be defined as the temperature at or above a given value in which a flammable liquid produces enough vapor to ignite by spark or flame and burn for at least five seconds. 

NOTE: At the fire point, the volatile liquid will continue to burn for at least 5 seconds after ignition by an open flame.

It is different from the flash point. Here the significant difference between them:

“Flash point explains the lowest temperature for ignition, but the ignition may not be sustained; whereas fire point explains the lowest temperature where ignition is achieved and the ignition sustained for some time”.

NOTE ALSO: The flash point is significantly lower than the it by usually 8 to 10 percent.