The use of enriched air mixtures, often called nitrox, has been getting more and more attention in the recreational diving community. This is especially true since major recreational diving organizations are starting to certify non-technical divers for oxygen-enriched nitrox diving. The decompression physiologists have explained both the risks and benefits of oxygen-enriched nitrox use in the diving literature. However, there are other risks that divers need to know about when using oxygen-enriched air. There is a belief in some groups in the diving community that any mixture less than 40 percent oxygen can be handled in the same manner as high pressure air.
This approach would include the use of materials are that are not very oxygen compatible, and little or no cleaning or contamination control. In this article, the authors would like to assert that this approach carries with it an unacceptable risk to the users of this equipment. To support this position, industry and professional society guidelines from ASTM, Compressed Gas Association, and The National Fire Protection Association are cited, as well as the results of research and testing. Recreational divers need to understand that as they increase the oxygen concentration in the mix, they also increase the chances of having a fire incident in their equipment. The recommendation is made that everyone involved in the design, use, servicing and refilling of oxygen-enriched diving gases must be aware of the additional hazards involved. This awareness will empower divers with the knowledge to make more informed choices about their equipment, and how it is maintained.