Which statement correctly differentiates the fire point from the ignition temperature?

Which statement correctly differentiates the fire point from the ignition temperature?

• A. Fire point is the lowest temperature at which vapor can ignite and sustain a continuous fire; ignition temperature is the lowest temperature at which fuel will ignite in air and continue to burn
• B. Fire point is the temperature at which fuel ignites in air; ignition temperature is the vapor ignition temperature
• C. Fire point is the temperature at which the material melts; ignition temperature is the temperature at which combustion begins
• D. Fire point is the pressure at which vapor ignites; ignition temperature is the point at which the flame becomes self-sustaining

Answer: (A)

The main idea is to distinguish how a flame starts versus how it can keep burning. The fire point is the temperature at which vapor can ignite and a flame can be sustained once ignition occurs, meaning you need an external ignition source to start the flame, and that flame can then continue. The ignition temperature (often called auto-ignition temperature) is the minimum temperature at which the fuel in air will ignite on its own, without an external flame or spark, and then continue to burn. This makes the given answer correct because it clearly separates the need for an ignition source to start a fire (fire point) from the heat alone causing spontaneous ignition in air (ignition temperature). Other statements mix up these ideas or bring in irrelevant concepts like melting or pressure, which do not define how fire initiation and sustained burning work.