Fire Tetrahedron

The fire tetrahedron and the fire triangle are frameworks or visual metaphors to help people understand the components of the combustion reaction. The combustion reaction is an exothermic (heat releasing) and redox (oxygen adding) chemical reaction between a fuel and an oxidant (usually atmospheric oxygen) that produces heat, light and smoke.

The fire tetrahedron describes the relationship between fuel, oxygen and heat by adding a fourth element; the chemical chain reaction to create a more comprehensive metaphor when compared with the fire triangle for understanding combustion.

1. fuel: Anything that can combust when it reaches a certain temperature, providing the material (fuel) necessary for combustion.
2. oxygen: A key element in the combustion process, oxygen from the air reacts with the fuel under the influence of heat, producing the flames of a fire.
3. heat: Heat is the energy required to increase the temperature of the fuel to a point where it can be ignited and continue to burn.
4. chemical chain reaction: The chemical chain reaction that forms part of the fire tetrahedron model refers to the process where the heat from the fire causes fuel molecules to break down and react with oxygen, releasing more heat and allowing the cycle to continue. This self-sustaining cycle is crucial for the ongoing combustion process.

The fire tetrahedron is an important concept in relation to fire safety because it helps us to develop strategies for fire detection (heat, smoke & light) and fire suppression by interrupting or interfering with any or all of the elements of the  tetrahedron.