Nitrox is a special breathing gas mixture that's available as an alternative to air. Nitrox is simply normal air that is blended with additional oxygen. This creates a breathing gas that contains less nitrogen and more oxygen than normal air.

Recreational Nitrox can be blended to contain as much as 40% oxygen. The most popular mixtures are EAN 32 and EAN 36. "EAN" stands for "Enriched Air Nitrox," and the number that follows indicates the mixture's oxygen percentage.