What is nitrox? Nitrox is a generic term used in the recreational dive world that refers to any breathing mixture of oxygen and nitrogen. The common form of nitrox seen in recreational diving is Enriched Air Nitrox, sometimes shortened to enriched air or just EANx, and specifically describes a gas mixture with a higher percentage of oxygen than air. EANx mixtures can contain anywhere from 22% to 99% oxygen with 32% and 36% oxygen being the most used blends and commonly written as EANx 32 and EANx 36 respectively. Enriched air nitrox is made one of two ways. One method is to remove nitrogen from an air sample to increase the concentration of oxygen; the other is to add pure oxygen to air to increase the oxygen percentage of the gas mix.
Like many forms of specialty diving, there are inherent risks that come with the many benefits of diving with nitrox which is why special training is required in the safe use and handling of enriched air. When diving with nitrox there is no actual difference in your dive skills; buoyancy, airway control, and swimming are all exactly the same. The main difference comes in dive planning to account for both the increased oxygen and decreased nitrogen.
The most common question I get about nitrox is if breathing nitrox means you can dive deeper, this is one of the most common misconceptions about enriched air. The primary benefit of diving with nitrox is increased bottom times at intermediate depths. This is possible due to the significantly lower concentration of nitrogen which means much less nitrogen can be absorbed into the blood and body tissues, however the increased amount of oxygen poses a risk. Under increased pressure oxygen becomes toxic and can attack your nervous system and is the limiting factor of your maximum depth. These risks can be easily avoided by sticking to your dive plan and staying within the limits of your nitrox mix. Enriched air nitrox is a great tool in the diver’s toolbox. It may not be necessary for every dive but when utilized properly it can greatly benefit your dive experience!