The flash point is the lowest temperature at which a liquid's vapors can be ignited in air.

The flash point is the lowest temperature at which a liquid's vapors can be ignited in air.

• A. The maximum temperature at which it can burn
• B. The temperature at which it will self-ignite
• C. The lowest temperature at which vapors can ignite
• D. The temperature at which it boils

Answer: (C)

Flash point is the minimum temperature at which the vapor above a liquid can mix with air and ignite in the presence of an ignition source. Below this temperature, there isn’t enough vapor to ignite; at or above it, ignition can occur if a flame or spark is present. This distinguishes it from autoignition, where a substance ignites without an external flame, and from the boiling point, which is about when the liquid turns to vapor regardless of ignition. So the description “the lowest temperature at which vapors can ignite” precisely reflects what the flash point measures.

Flash point is the minimum temperature at which the vapor above a liquid can mix with air and ignite in the presence of an ignition source. Below this temperature, there isn’t enough vapor to ignite; at or above it, ignition can occur if a flame or spark is present. This distinguishes it from autoignition, where a substance ignites without an external flame, and from the boiling point, which is about when the liquid turns to vapor regardless of ignition. So the description “the lowest temperature at which vapors can ignite” precisely reflects what the flash point measures.