The production of NITROX mixtures is restricted to persons who have completed the special gas mixing course, who are certified to work with oxygen and who have the appropriate certification.
NITROX oxygen-enriched mixtures, containing less than 40% oxygen, do not require any special equipment. You can use your regular equipment. The only exception is a dive computer.
When using mixtures, you need to use special dive computers with a variable %02 setting for the mixtures to be used. But this does not mean that you have to have two computers. By setting the oxygen content of the Nitrox computer to 21 (air), you can use it for “open air” diving.
Mixed cylinders must be differentiated from air cylinders to avoid confusion, as accidental use of an air cylinder instead of a mixture of NITROX . The longer dive time will result in decompression sickness. If you mistakenly use NITROX mixture instead of air and exceed the oxygen depth limit of the mixture, oxygen intoxication of the central nervous system (CNS) may occur.
There is an internationally accepted standard for marking cylinders designed for mixtures with an oxygen content greater than 21%. This is either a wide green band around the top of the cylinder with the yellow NITROX, ENRICHED AIR NITROX or SAFE AIR NITROX® lettering, or one of these lettering in large green letters vertically across the length of the yellow cylinder. More often than not, standard stickers are used so as not to paint the cylinders.