An extremely common question I see is whether or not certain gear (mainly regulators) can operate with enriched air / Nitrox. Many manufacturers even claim in their manual that Nitrox is not supported.

It is commonly accepted amongst scuba diving professionals that mixes with less than 40% oxygen are treated as air (with respect to equipment). Enriched air specialties only qualify you to use up to 40%. This means your "air-only" regulator is perfectly fine with any recreational Nitrox mix. No special assemblies or upgrades required, and your tank will not explode on your back underwater.

Interestingly, the flip side of the above "rule" is that any mixes with more than 40% oxygen are treated as pure oxygen.