Diving

Both professional SCUBA divers and people who enjoy diving as a leisure activity use pressurised air. This air is usually produced by compressors and is subsequently passed through a simple purification unit to remove large quantities of moisture and any oil that may be present. It will, therefore, be no surprise to anyone that this air must meet a number of criteria in order to ensure the safety and health of the divers using it.

The international EN 12021 standard has been specially developed to guarantee the quality of this air, as is evident from the scope of this standard:

EN 12021:1998
1 Scope
This European Standard specifies requirements for the quality of compressed air supplied for use with the following types of equipment:
a) Respiratory protective devices - Self-contained open-circuit compressed air breathing apparatus and open-circuit compressed air underwater breathing apparatus (SCUBA);
b) Respiratory protective devices - Compressed air line breathing apparatus and compressed air line breathing apparatus for use under water;
c) Respiratory protective devices for escape - Self-contained open-circuit compressed air breathing apparatus including full face mask or mouthpiece assembly or hoods.

Among other things, this standard sets requirements for the levels of oxygen, water, oil, carbon monoxide and carbon dioxide in breathing air. However, we have learned from practice that matters such as dust (particles), volatile hydrocarbons and micro-organisms also affect this special form of breathing air.