1 DESCRIPTION: Sarin (military designation GB) is a nerve agent that is one of the most toxic of the known chemical warfare agents.2  It is generally odorless and tasteless. 3  Exposure to sarin can cause death in minutes. 4  A fraction of an ounce (1 to 10 mL) of sarin on the skin can be fatal. DESCRIPTION: Sarin (military designation GB) is a nerve agent that is one of the most toxic of the known chemical warfare agents.