TecEvolution, More about Enriched Air Nitrox (EANx)

Enriched Air (Nitrox) is air that has a higher oxygen content. Originally introduced by the National Oceanographic and Atmospheric Administration (NOAA) for research diving, nitrox is now widely accepted within the dive community. Typically, air contains two major components... oxygen (21%) and nitrogen (79%). Commonly referred to as nitrox, enriched air for recreational diving is considered blends of 22% to 40% oxygen. For Technical Diving Nitrox is either used as a bottom gas, with mixes usually containing less than 40% or as a decompression gas, with mixes containing from 40% to 100% Oxygen.

Divers all over the World share a common goal : spending as long as possible underwater. As Enriched air Nitrox contains more oxygen (metabolised gas) and less nitrogen (inert gas), when it is used during the bottom phase of a dive, it maximizes no decompression (or reduces decompression obligations) time and reduces fatigue due to the inferior Nitrogen load in the body. During decompression, it is used for accelerated decompression, by creating a higher partial pressure gradient in between the gas in the lungs and the dissolved gas in the body, which accelerates off-gasing (dissolved gas escaping into surrounding environment).

Unfortunately, enriched air Nitrox also has a potential risk, and diving enriched air nitrox requires particular training, planning and procedures. Training to these dangers and procedures for mixes ranged in between 21% and 40% oxygen content is part of Enriched Air Nitrox Diver Course and training to dangers and procedures for mixes containing over 40% is reserved to technical dive courses

Enriched Air Nitrox can be obtained from any Gas Blending Facility, and blending nitrox requires special training. The nitrox cost is usually on a per tank fill basis. These facilities can use different methods to obtain the desired gas mix. The most common blending methods in Thailand being partial pressure and continuous flow blending methods.