>French

>verification combined with thorough planning of your maximum operating depth
>are necessary to avoid complications while diving on nitrox.
>Last year DAN researchers analyzed nearly 400 U.S. recreational diving fatalities over a 10-year period to examine the occurrence of oxygen-toxicity seizures. Were those fears some people expressed in the early days justified? The final data set studied included 344 air divers (86 percent) and 55 nitrox divers (14 percent), ages 14 to 78. The average oxygen content in the nitrox was 31 percent.
>The researchers found that the nitrox divers were more commonly diving in equipment they personally owned and that the depth of the fatal dives was significantly deeper for the nitrox divers than for the air divers. This finding seemed counterintuitive at first, since the safe maximum operating depth of nitrox is shallower than that of air, but when you factor in the cost of a nitrox fill (which is typically more expensive than air), it makes sense that divers going to shallow depths with longer no-decompression limits would be less likely to pay extra for nitrox.
>In the past 25 years nitrox has gone from being warily regarded to being the gas of choice in many dive operations. It would have been difficult to imagine 30 years ago that today liveaboard dive boats would be organizing thousands of dives on nitrox. We estimate U.S. divers make millions of dives each year while breathing nitrox. While oxygen toxicity may have caused more fatalities than DAN is aware of, research shows that the fears expressed when nitrox was first used in recreational diving have not been realized. There can be little doubt this is due to the entire diving community working together: the gas blenders getting the mix right, instructors teaching how to safely dive with nitrox, and divers knowing to analyze their gas when they collect it from the shop and planning their maximum operating depth accordingly.
>Note: The full paper reporting this study appeared in the March 2017 issue of the medical journal Brain Injury and was described at the 2017 annual scientific meeting of the Undersea and Hyperbaric Medical Society as one of six highlight papers of the year. DAN congratulates the nitrox diving community for maintaining safe nitrox diving practices. We urge everyone to remain vigilant: Always analyze the oxygen content, and clearly mark it and the maximum operating depth on the tank.
>Reference: Buzzacott P, Denoble PJ. Possible central nervous system oxygen toxicity seizures among US recreational air or enriched air nitrox open- circuit diving fatalities 2004-2013. Brain Injury 2017; 31(3):366-369.
>© Alert Diver — Q2 Spring 2018