Sarin nerve agent molecule. Molecular model of the chemical weapon nerve agent sarin, also known as GB. It can be absorbed through the skin, inhaled, ingested or injected. It acts by inhibiting acetylcholinesterase, the enzyme that degrades the neurotransmitter acetylcholine. This leads to an accumulation of the neurotransmitter and overstimulation of the nervous system. Exposure results in loss of control over bodily functions, twitching, coma and, even at low concentrations, death. Atoms are colour-coded: carbon (grey), hydrogen (white), oxygen (red), phosphorous (orange) and fluorine (light blue).