Argon is a non-flammable, colorless, odorless, chemically inactive gas which comprises less than 1.0% of the atmospheric air. Commercial argon is the product of air separation, where liquefaction and distillation produce a grade of low purity from which oxygen must be removed (by combining it with hydrogen to produce water).

Argon is widely used as a fill gas in incandescent and fluorescent lamps, and is an inert shielding gas for arc welding to protect the weld from contaminants.