Tennessee Firefighter 64-Hour Program (TN FF 64HR) Final Test Practice

In a combustion reaction, oxygen is a crucial component necessary to sustain a fire. Oxygen supports the chemical process of oxidation that occurs when fuel is burned. The classic fire triangle illustrates that fire requires three elements: fuel, heat, and oxygen. While heat and fuel are essential, without oxygen, the combustion process cannot continue.

Oxygen combines with the fuel to release energy in the form of heat and light, which is what we observe as fire. In a typical fire, the air contains about 21% oxygen, which is sufficient to sustain the combustion reaction. If the concentration of oxygen is reduced below a certain level—typically around 16%—the fire will extinguish since the combustion cannot be maintained.

This understanding highlights the importance of oxygen in the process of combustion, making it the fundamental requirement for sustaining fire.