American Chemical Society, an organization of chemists and chemical engineers. It is the largest scientific society in the world. Its aims include the encouragement of research; the raising of the standards of professional ethics, education, and achievement; and the increase and spread of chemical knowledge. The society has over 30 professional divisions. Its numerous publications include Chemical and Engineering News, Journal of the American Chemical Society, and Chemical Reviews. The society was founded in 1876. Membership is over 160,000 in the United States and Puerto Rico. Headquarters are in Washington, D.C.