Fire is a rapid, self-sustaining chemical reaction (oxidation) that requires four components—fuel, oxygen, heat, and a chain reaction—collectively known as the fire tetrahedron. Removing any element causes the fire to extinguish. It is characterized by the release of light and heat.  The Four Components (Fire Tetrahedron): Fuel: Any combustible material (solid, liquid, or gas). Solid fuels undergo pyrolysis to release gases, while liquids undergo vaporization. Oxygen: Oxidizing agent; air typically contains ~21% oxygen, and at least 16% is needed for combustion. Heat: Energy source... Show more

Fire is a rapid, self-sustaining chemical reaction (oxidation) that requires four components—fuel, oxygen, heat, and a chain reaction—collectively known as the fire tetrahedron. Removing any element causes the fire to extinguish. It is characterized by the release of light and heat. 

The Four Components (Fire Tetrahedron):
Fuel: Any combustible material (solid, liquid, or gas). Solid fuels undergo pyrolysis to release gases, while liquids undergo vaporization.
Oxygen: Oxidizing agent; air typically contains ~21% oxygen, and at least 16% is needed for combustion.
Heat: Energy source required to reach the ignition temperature and maintain the chemical reaction.
Chemical Chain Reaction: The ongoing interaction between the heat, fuel, and oxygen that keeps the fire burning. 

Fire Behaviors & Stages:
Heat Transfer: Fire spreads via conduction (contact), convection (fluid movement), and radiation (electromagnetic waves).
Stages: Ignition, growth, fully developed, and decay.
Extinguishing Methods: Removing heat (water), removing oxygen (smothering/foam), removing fuel, or breaking the chemical chain reaction (dry powder). 

Common Fire Terms:
Flash point: Lowest temperature a liquid gives off sufficient vapors to ignite.
Pyrolysis: Chemical decomposition of solid matter by heating.
Oxidation: Chemical combination of a substance with oxygen.

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