## Nitrox Enriched Air Nitrox \(EAN\) is a ==gas mixture where the nitrogen is underweight in profit of oxygen==. The oxygen concentration depends on of the depth you want to go, which is called MOD for Max Operating Depth. I'll talk later on this but, just like nitrogen, oxygen can become toxic by going deeper and result in hyperoxia, which is caused by the excess of oxygen supply. The more oxygen concentration there is in the tank, the less depth you can go. In recreational diving, we're mostly using a mixture with 32% of oxygen \(said "Nitrox 32"\). It allows us a MOD of -34 m if we aknowledge a maximum oxygen [partial pressure](Partial%20pressure.md) of 1.4. Nitrox is prepared with specific gear, such as permeable membrane filter or low pressure oxygen injection and need to be prepared by trained people. When we're starting to prepare our equipment for diving, we need to measure the oxygen rate in the bottle using a gas analyzer, and stick to our bottle a sign with our parameters written like this : EAN 32% MOD -34 m. This is mostly needed to inform other divers.  Here're **the pros** of using Nitrox for diving : * As there is less nitrogen, we can stay longer at our MOD without the need to make decompression stops. So basically, this mean that we can explore more 😊. * It decreases the risk of nitrogen narcosis and decompression sickness * It reduces post-dive fatigue \(the body need to expel less nitrogen\) * It decreases the risk of accident for people who have a [PFO \(patent foramen oval\)](https://www.heart.org/en/health-topics/congenital-heart-defects/about-congenital-heart-defects/patent-foramen-ovale-pfo) * There's no noticeable change in terms of breathing comfort. * As there's less decompression stops, it maximize the exploration time And **the cons** : * More oxygen means more risk of [hyperoxia](Hyperoxia.md) and high-pressure nervous syndrome. * Contrary to popular belief, Nitrox don't allow us to go deeper. Rather the opposite. * Diving club charge for Nitrox preparation, so it has an economic disadvantage. **Links :** * [Nitrox - Wikipedia](https://en.wikipedia.org/wiki/Nitrox) * [How is Nitrox made?](https://www.youtube.com/watch?v=7TYlcLmlvno) * [Nitrox tank preparation : marking and identification](https://www.tdisdi.com/sdi-diver-news/nitrox-tank-preparation-marking-and-identification/) * [How to calculate Maximum Operating Depth \(MOD in scuba diving\)](https://www.globosurfer.com/maximum-operating-depth/)