Even though you will not be using nitrox mixtures above 40% oxygen, why should your cylinder be oxygen cleaned and identified as a nitrox cylinder?

The rationale behind having your cylinder oxygen cleaned and identified as a nitrox cylinder, even if you will not be using mixtures above 40% oxygen, centers on safety considerations regarding the potential for exposure to pure oxygen at elevated pressures. When filling a cylinder for nitrox use, there is a chance that higher concentrations of oxygen might accidentally be introduced, especially if the filling or mixing procedures are not carefully adhered to.

Oxygen cleaning helps eliminate hydrocarbons and other contaminants that may ignite in the presence of high concentrations of oxygen, particularly under pressure. The identification of the cylinder as a nitrox cylinder ensures that anyone handling or filling the cylinder is aware of its specific use and the need to maintain safe practices concerning oxygen exposure. This precautionary measure is vital because it mitigates the risk of combustion and ensures compliance with safety standards in diving operations involving enriched oxygen mixtures.

Thus, the requirement for cleaning and proper identification serves to protect the diver and ensure safe diving practices in any scenario involving nitrox.