Sarin (NATO designation GB [short for G-series, "B"]) is an extremely toxic organophosphorus compound. [4] A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent.Exposure can be lethal even at very low concentrations, where death can occur within one to ten minutes after direct inhalation of a lethal dose, [5] [6] due to suffocation from ...