Carbon Dioxide (CO2) - a nonflammable, colorless, odorless gas. Found in air at concentrations of about 0.03%, carbon dioxide may exist simultaneously as a solid, liquid and gas. Carbon dioxide is used as a shielding gas in the arc welding process. It's the source of the bubbles in soft drinks and other carbonated beverages. And it's used to fill certain types of fire extinguishers that rely on its inert properties, density, and low temperature when released from high pressure storage. In addition to its inert properties, carbon dioxide, as dry ice, is used to freeze a variety of foods. Carbon dioxide is sold by weight (lbs.) and available in high pressure and liquid cylinders, as well as Micro Bulk and bulk deliveries.