Carbon Dioxide

Carbon Dioxide (CO₂)

Carbon dioxide is the most versatile of all gases. Its physical and chemical properties, and its ability to be processed into a liquid, gas or solid, make it ideal for a variety of diverse applications. It is normally stored as a liquid and can exist only as a solid or gas at room conditions. Carbon dioxide has a low temperature (-109° F as a solid), is highly inert under most conditions, and although basically non-reactive, becomes chemically active when exposed to moisture or high heat. Carbon dioxide is a compound of carbon and oxygen in proportions by weight of about 27.3 percent carbon to 72.7 percent oxygen. At normal atmospheric temperatures and pressures, carbon dioxide is colorless, odorless and about 1.5 times as heavy as air. Carbon dioxide is sensed by some persons as having a slight pungent odor and biting taste. It is normally inert and nontoxic.

The Compressed Gas Association (CGA) specification G-6.2, Grade H (99.8 percent pure) is considered standard for “commercial” carbon dioxide.

Carbon dioxide is used to freeze and chill food rapidly. The carbonated beverage industry is a major customer for Carbon dioxide. Oil recover operations and pH control/water treatment use CO₂ also.

It is supplied in bulk stations, dewars and as a liquefied compressed gas.

Safety

Carbon dioxide is essentially nontoxic but may cause increased breathing and heart rates. Breathing concentrated amounts may also cause nausea and unconsciousness. The major hazard of carbon dioxide is asphyxiation when CO₂ has built up in an area and displaced the air (oxygen) needed for breathing. When oxygen levels are below 19.5 percent brain damage and death may occur. It is an inert gas that cannot usually be sensed by odor, color or taste although some people claim it has a slightly pungent odor. It is difficult to know when carbon dioxide is present and when it may be depleting oxygen needed for breathing. It must be used in well-ventilated areas. Efforts must always be made to avoid leaks or venting of these gases in confined spaces.

Do not work with any inert gases in confined spaces such as tanks, pits or tunnels unless an adequate breathing air supply is available. Always provide good ventilation in enclosed areas where inert gases may be present. The eyes and lungs are especially sensitive to the cold vapors. Wear protective goggles, gloves and clothing when handling CO₂ or when cold liquid might be spilled or splashed.