Oxygen Deficiency

Oxygen deficiency means that there is not enough oxygen to breathe. It can cause victims to become confused, fatigued, or to collapse.

The "normal" air that we breathe contains a mixture of different gases.

Generally, any time the oxygen content of the air falls below 19.5%, the atmosphere is considered to be oxygen-deficient.

Oxygen deficiency can occur when oxygen is "used up" in the confined space. For example, when:

• Open flames like cutting torches inside the space use the oxygen for the process of combustion, which is called oxygen consumption.
• Oxygen is soaked up, or adsorbed by products like activated carbon.
• Oxidation processes occur, like rusting metal.
• Biological processes occur, like rotting leaves or decaying organic matter.

To learn more about Firefighter Confined Space visit our Firefighter Confined Space Entry & Rescue Online Training web page.