carbon dioxide (CO2) [L, carbo + Gk, dis, twice, oxys, sharp] , a colorless, odorless gas produced by the oxidation of carbon; also a “greenhouse” gas. Carbon dioxide, as a product of cell respiration, is carried by the blood to the lungs and is exhaled. The acid-base balance of body fluids and tissues is affected by the level of carbon dioxide and its carbonate compounds. Solid carbon dioxide (dry ice) is used in the treatment of some skin conditions. Normal adult blood levels of carbon dioxide are 23 to 30 mEq/L or 23 to 30 mmol/L (SI units). See also greenhouse effect.
