Nitrox is a breathing gas made by blending oxygen and nitrogen.

The name “Nitrox” comes from combining NITR (from nitrogen) and OX (from oxygen).

A gas mixture with a higher oxygen percentage than air is commonly referred to as high-oxygen Nitrox.

High-oxygen Nitrox is also called Enriched Air Nitrox—often shortened to “Nitrox”—and is written as EAN.

For recreational diving, the most commonly used Nitrox mixes are 32% and 36% oxygen, as released by the United States Oceanic and Atmospheric Administration for private divers.

These mixes are written as EAN32 and EAN36.