Cyclosarin or GF (cyclohexyl methylphosphonofluoridate) is an extremely toxic substance used as a chemical weapon. It is a member of the G-series family of nerve agents, a group of chemical weapons discovered and synthesized by a German team led by Dr. Gerhard Schrader. Like its predecessor sarin, cyclosarin is a liquid organophosphate nerve agent. Its physical characteristics are, however, quite different from sarin. At room temperature, cyclosarin is a colorless liquid whose odor has been variously described as sweet and musty, or resembling peaches or shellac. Unlike sarin, cyclosarin is a persistent liquid, meaning that it has a low vapor pressure and therefore evaporates relatively slowly, about 69 times slower than sarin and 20 times slower than water. Cyclosarin (GF) also demonstrates greater toxicity than sarin (GB) in humans.