Soda ash is known chemically as sodium carbonate, an important inorganic chemical. It has been produced for several centuries by processing certain vegetation and minerals. The U.S. soda ash industry has evolved from several small sodium carbonate mining operations in the west. Now, a nucleus of six companies produce about one-fourth of the world's annual soda ash output. U.S. producers currently dominate the world market. But certain international events are occurring that will reshape the domestic soda ash industry in the next decade.