Areas of Expertise - Air Composition & Common Air Contamination Sources

Air Composition:

Clean, Natural Air is an odorless, colorless gas mixture. Excluding water vapor levels, which vary greatly, three major components of dry air: Nitrogen @ 78.09% Oxygen @ 20.95% and Argon @ 0.93% make up about 99.97% of it's composition. An important minor component of natural air is Carbon Dioxide @ 0.03% (300 ppm). Trace gases in clean, natural air include: Methane @ 0.0002% (2 ppm) & less than 0.0001% (1 ppm) of Hydrogen, Nitrous Oxide, Ozone and some noble gases. Synthetic Air is also used in SCBA/SCUBA applications. This type of air is produced by blending Nitrogen and Oxygen gases in the proper proportions.

The importance of clean breathing air in sustaining life and maintaining good health is well known. The dangers associated with breathing contaminated air are also well known and are especially critical when using SCBA tanks in emergency situations. To insure SCBA air quality, NFPA 1404 (Sec. 7-1.1) requires a minimum CGA G-7.1 Grade "D" air quality and at least a 3 month air sampling schedule as well as a test record maintenance program. Many Fire and Rescue Dept. programs have opted to use CGA G-7.1 Grade "E" (the minimum SCUBA grade for diving to 130 ft.) as their minimum SCBA air standard.

Common Air Contamination Sources:

Industrial emissions, vehicle exhaust, combustion heating activities, and local environmental conditions can seriously degrade the quality of intake air used during compression. Compressor equipment, malfunctions, poor maintenance or operational practices can also introduce contaminants into SCBA / SCUBA air tanks.