What defines the lowest temperature at which a liquid's vapor can ignite with an open flame?

The flash point is defined as the lowest temperature at which a liquid's vapor can ignite when exposed to an open flame or ignition source. It is a critical characteristic in understanding the flammability of a liquid. The significance of the flash point lies in safety assessments and risk management for handling and storing flammable liquids. Knowing the flash point helps determine safe operating temperatures and protocols for preventing potential fire hazards.

In comparison, other terms have different meanings. The boiling point refers to the temperature at which a liquid turns into vapor, regardless of ignition potential. Ignition temperature, or autoignition temperature, is the minimum temperature at which a substance will spontaneously ignite without an external flame or spark. Vapor pressure is a measure of the tendency of a substance to evaporate at a given temperature and is relevant in assessing how much vapor is produced, but it does not specifically define the temperature for ignition. Understanding these distinctions is vital for effectively managing hazardous materials.