The Truth About Nitrox: Is It Actually Safer for Older Divers?
DAN (Divers Alert Network) explains that Nitrox can provide an additional safety margin against decompression stress because it contains less nitrogen than air. If a diver makes the same depth and duration dive on Nitrox that they would have made on air, they absorb less nitrogen.
DAN also specifically notes that older divers are more prone to developing venous gas bubbles after diving, and that if they experience decompression sickness, healing may take longer or be incomplete. However, DAN points out that older divers actually have proportionally fewer DCS cases because they tend to dive more conservatively.
DAN supports Nitrox as a tool that can reduce nitrogen exposure and decompression stress, which can be particularly attractive for older divers, but DAN does not characterize Nitrox as inherently safer simply because a diver is older.
The important distinction (DAN makes this point very clear):
Nitrox used at air-table limits = increased safety margin.
Nitrox used to extend bottom time = that safety margin is largely used up.
For example, if an older diver normally plans a 60-minute dive on air and instead uses Nitrox while still following the air no-decompression limits, the diver has reduced nitrogen exposure. That's the situation in which DAN describes a decompression-safety benefit.
DAN also cautions that Nitrox introduces oxygen-toxicity considerations and requires appropriate training and attention to maximum operating depth.
Nitrox may be an especially useful tool for mature divers because it reduces nitrogen exposure and can provide an additional decompression safety margin when used within air-table limits. DAN emphasizes, however, that Nitrox isn't automatically safer, it must be used correctly and within its maximum operating depth.
That's stronger and more accurate than saying Nitrox simply is “a safer gas for older divers.”
DAN: Nitrox Diving Safety
