The Fire Tetrahedron


In Lesson 1, you learned of the four elements that make up a fire.  Remember that they are: fuel, oxygen, heat, and chemical reaction.  Removing any of the four elements, will stop the chemical process and cause the fire to go out.  These four important elements, are often represented in a four-sided figure called a fire tetrahedron.

At its most basic, fire safety is focused on the principle of keeping the four elements from combining to produce combustion.

Fires can be extinguished if:

  • the fuel is restricted
  • oxygen is consumed and not replaced
  • heat is dissipated or not allowed to build up
  • the chemical reaction is stopped when the free radicals are removed

These are the main principles behind modern firefighting techniques.  You will learn more about extinguishing a fire later in this unit.