Ethyl carbamate (also known as urethan and urethane), formerly marketed as an inactive ingredient in Profenil injection, was determined to be carcinogenic and was removed from the Canadian, US, and UK markets in 1963. (en)
Norton A. Cashen, "Method of producing anhydrous crystalline reaction products of formaldehyde and methyl-, ethyl carbamate." U.S. Patent US4002668, issued July, 1973. (en)