The temperature of a pure liquid at which point its vapor pressure is equal to or slightly greater than atmospheric pressure. Boiling occurs when a temperature is reached at which the thermal energy of the particles is great enough to overcome the cohesive forces that hold them in the liquid. Most common ignitable liquids consist of mixtures of hydrocarbon compounds; such mixtures are described as having a "boiling range". As an example, gasoline is described as having a boiling range of -45 degrees F to over 400 degrees F. This means that the lightest compound of gasoline boils at -45 degrees F and the heaviest of the more than 300 individual compounds in gasoline boils at more than 400 degrees F
