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Elements of Fire

The phenomena of fire are complex, but they may be described by major characteristics: rapid oxidation with the evolution of heat and light. A knowledge of the conditions that determine whether this rapid oxidation will take place with any material is essential for understanding the principles underlying fire prevention, control and extinguishment.

Every combustible substance has temperatures at which combustion can take place. They fall into three categories, namely: flash point, fire point and spontaneous ignition temperature.

The flash point of a substance is the lowest temperature at which it will give off enough vapours to produce a momentary flash of a small fire. There are several types of apparatus for determining the flash point of a material.

The fire point is the lowest temperature at which a substance will continue to burn when ignited. The fire point is generally slightly above the flash point.

Spontaneous ignition temperature of a substance is the lowest temperature at which its vapour, usually a gas generated through the application of heat, will ignite independently of any external source of ignition. A substance or its vapour, however, does not have to be heated in order to be ignited.

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