Chapter II: Health and safety guarantees

Breathing gases and mixtures are as follows: 1° Binary mixtures : – nitrox is a breathing mixture composed of oxygen and nitrogen in different proportions to air; – heliox is a breathing mixture composed of oxygen and helium; 2° Ternary mixtures: trimix, a breathing mixture composed of oxygen, nitrogen and helium; 3° Pure oxygen, used in rebreathers and for decompression.

The conditions for diving with oxygen and mixtures other than air are set out in annexes III-17 a, III-17 b, III-17 c, III-18 a, III-18 b and III-18 c.

The minimum partial pressure of oxygen inspired by the diver is limited to 160 hectopascals (0.16 bar). The maximum partial pressure of oxygen inspired by the diver during immersion is limited to 1,600 hectopascals (1.6 bar).

Cylinders are identified according to the gases contained. The manufacturer or distributor of a breathing mixture other than air shall record the following information on the identification sheet for each cylinder and in the establishment’s register: – the percentage of oxygen analysed and the theoretical composition of the gas mixture ; – the date of analysis; – the name of the manufacturer or distributor. Before diving, the end user completes…

When diving is carried out using rebreathers, these are certified in accordance with current standards. After having completed a qualifying course, adapted to the rebreather in question, from the Fédération française d’études et de sports sous-marins, the Fédération sportive et gymnique du travail, the Union nationale des centres sportifs de plein air, the Association nationale des moniteurs de plongée or the Syndicat national des moniteurs de plongée, or recognised by…