Butadiene is a colorless, non-corrosive gas with mild aromatic or gasoline-like odor. Butadiene is a simple conjugated diene and is a flammable gas. Butadiene vapor pressure is 2100 mmHg at 25 °C and the explosive limits are 2-11.5%. Butadiene is slightly soluble in water (735 mg/liter) and is soluble in a number of organic solvents such as diethyl ether, ethanol, benzene, acetone and polar and nonpolar organic solvents. The butadiene can be extracted from C4 hydrocarbons, dehydrogenation of n-butane, ethanol and butenes. The butadiene can be extracted from crude C4, a product from the steam cracker. A hydrocarbon used as feed in the production of butadiene determines the quantity of butadiene. Light feeds, such as ethane produce ethylene when cracked. On the other hand, heavier feeds produced the heavier olefins, butadiene, and aromatic hydrocarbons. Butadiene can also be extracted by the catalytic dehydrogenation of normal butane (n-butane). Butadiene from n-butane is commercially produced using the Houdry catadiene process, which was developed during World War II. Butadiene is also produced from ethanol. Smaller-capacity plants use ethanol for the production of butadiene due to the lower capital cost associated with it in comparison to others. 1,3-Butadiene can also be produced by catalytic dehydrogenation of normal butenes. This method was also used by the United States Synthetic Rubber Program (USSRP) during World War II. The process was much more economical than the alcohol route but competed with aviation gasoline for available butene molecules. The USSRP constructed several plants in Baton Rouge and Lake Charles, Los Angeles; Houston, Baytown, and Port Neches, Texas; and Torrance, California. Butadiene is a raw material that can be used to produce synthetic rubber. The tire industry is one of the main consumers of butadiene. Other applications for butadiene include plastics production and paper chemicals.