What is the EANx designation when referring to Nitrox?

The EANx designation stands for Enriched Air Nitrox. This term refers to a blend of nitrogen and oxygen used in diving, where the oxygen content is higher than that of regular air. Standard air is composed of approximately 21% oxygen and 79% nitrogen, while Enriched Air Nitrox typically contains between 22% and 40% oxygen.

Using Enriched Air Nitrox allows divers to extend their no-decompression limits and reduce nitrogen absorption, which can lead to a decrease in the risk of decompression sickness. This is particularly beneficial for deep dives or for dives that require multiple repetitive trips to depth.

Other terms in the choices could potentially be misleading. For example, Extended Air Nitrox and Enhanced Air Nitrox are not recognized terms within the diving community, and they do not accurately describe the gas mixture or its benefits. Extra Air Nitrox also does not align with the established terminology used in scuba diving. The established and widely accepted designation is indeed Enriched Air Nitrox. Understanding this terminology is crucial for divers to communicate effectively about gas mixtures and ensure safety during dives.