Flash point

The lowest temperature at which a liquid produces enough vapor to ignite briefly when exposed to an ignition source. It indicates fire hazard, not whether the liquid will sustain combustion.

Vapor pressure: The pressure exerted by a vapor in equilibrium with its liquid or solid phase. A liquid’s vapor pressure rises with temperature, increasing the flammable vapor available above it.
Flammable liquid: A liquid that can produce ignitable vapor under specified conditions. Flash point helps classify liquids according to their fire hazard.
Combustion: A chemical reaction in which a fuel reacts with an oxidizer and releases heat, often with light. Flash point concerns the onset of brief ignition within the broader process of combustion.
Evaporation: The transition of molecules from a liquid surface into the gas phase. Evaporation supplies the vapor that can mix with air and ignite.
Flammability limits: The lower and upper concentrations of a gas or vapor in air that can support flame propagation. Flash requires vapor in air to reach an ignitable concentration near the liquid surface.
Globally Harmonized System of Classification and Labelling of Chemicals: An international framework for classifying chemical hazards and communicating them through labels and safety data sheets. Its flammable-liquid categories use flash-point thresholds alongside boiling-point criteria.
Flame point: A temperature measure associated with a liquid’s vapor igniting when exposed to a test flame. The term is sometimes used for the sustained-burning threshold called fire point.
Ignition: The initiation of combustion in a fuel–oxidizer mixture. A test flame or spark supplies the external energy required for a flash.
Autoignition temperature: The lowest temperature at which a substance ignites in air without an external ignition source. Unlike flash point, it concerns ignition without a spark or flame.
Safety data sheet: A document describing a chemical’s hazards, handling, storage, and emergency measures. Flash point is commonly reported in the physical and chemical properties section.

Linked from 28 pages