Tabun or GA (Ethyl N,N-dimethylphosphoramidocyanidate) is an extremely toxic substance. It is a clear, colorless, tasteless liquid with a faint fruity odor. Because it fatally interferes with normal functioning of the mammalian nervous system, it is classified as a nerve agent. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN Resolution 687, and its production is strictly controlled and stockpiling outlawed by the Chemical Weapons Convention of 1993. Tabun is the first of the so-called G-series nerve agents (along with GB (sarin), GD (soman) and GF (cyclosarin)).