Which term describes the temperature at which vapors will continue to burn after ignition?

• A. Flash point
• B. Boiling point
• C. Fire point
• D. Ignition temperature

Answer: (C)

When thinking about flammability temperatures, the important idea is sustaining a flame after ignition. The fire point is the temperature at which the vapors released by a liquid will continue to burn after being ignited, meaning the flame is self-sustaining. Below this temperature the flame may flash on briefly but will go out because there isn’t enough vapor or energy to keep burning. The flash point is lower and only marks the point where vapors can ignite in air momentarily, not where the flame will stay alight. The boiling point is about when the liquid turns to vapor, not about ignition. The ignition temperature (autoignition) is the temperature at which a substance will ignite without an external flame, which is a different concept from maintaining combustion after ignition. So the term that describes vapors continuing to burn after ignition is the fire point.