TABLE 1
Composition of clean, dry air near sea level*

 

Component Content Component Content
  % by Vol. ppm   % by Vol. ppm
Nitrogen 78.09 780,900 Hydrogen .00005 0.5
Oxygen 20.94 209,400 Methane .00015 1.5
Argpm .93 9,300 Nitrogen Dioxide .0000001 0.001
Carbon Dioxide .0318 318 Ozone .000002 0.02
Neon .0018 18 Sulfur Dioxide .00000002 0.0002
Helium .00052 5.2 Carbon Monoxide .00001 0.1
Krypton .0001 1 Ammonia .000001 0.01
Xeon .000008 0.08      
Nitrous Oxide .000025        

*From Cleaning Our Environment the Chemical Basis of Action, American Chemical Society, Washington, D.C., 1969 page 24.