This document discusses the fire tetrahedron and the factors necessary for fire. It explains that a fire needs fuel, oxygen, heat, and a chain reaction to sustain burning. An uncontrolled fire occurs when these factors are present without limits, while controlling any one of the factors can prevent a fire. The flammability limits refer to the minimum and maximum concentrations of fuel and oxygen required to maintain a fire.

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26. -Fuel (Combustible
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-Heat (Sources of Ignition)
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-Air (Oxygen)
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27. controlled fire

28. Chain Chemical Reaction
uncontrolled fire
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Fuel (Combustible Substances)
-Air (Oxygen)
-Heat
(Sources of Ignition)
-Chain
Chemical Reaction

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(Flammability Limits)
(LEL)(UEL)

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