What Is Sarin?

CDC says sarin, known to the military as GB, is a human-made chemical warfare nerve agent and one of the most toxic and fast-acting nerve agents. Nerve agents stop certain enzymes from working, so muscles are constantly being used and people may become tired and no longer able to keep breathing. Sarin is a clear, colorless, tasteless liquid with no smell, so people may not know they were exposed until signs and symptoms develop.

CDC says exposure to a low or medium amount can cause symptoms within seconds to hours, including blurry vision, chest tightness, confusion, drooling, difficulty breathing, excessive sweating, muscle cramps, small pinpoint pupils, tremors and weakness, and that even a small drop on the skin can cause sweating and muscle twitching where it touched. It says large doses by any route would likely cause loss of consciousness, convulsions, coma, paralysis and cardiac arrest or respiratory failure possibly leading to death. ATSDR says incapacitating effects of nerve agents occur within 1 to 10 minutes, and fatal effects can occur within 1 to 10 minutes for agents including GB.

For an outdoor release, CDC says that if you cannot go indoors, leave the area, and if you cannot get away, go to the highest ground possible, because sarin is heavier than air and sinks to lower areas. If the release was indoors, it says to get out of the building. It says taking off all clothes, jewelry and accessories, blotting any liquid and showering is the best way to remove sarin from the body, and that treatment involves removing sarin and providing supportive care, with antidotes available in healthcare settings that are most useful when given as soon as possible after exposure.

CDC says sarin breaks down slowly in the body, so repeated exposures can build up, and that people exposed to low amounts usually recover while those exposed to higher amounts may have long-lasting muscle weakness, paralysis, pain and pins and needles sensations. A 2020 study describes the 1995 Tokyo subway sarin attack as an unprecedented act of terrorism that killed 13 people and sickened more than 6,000, and found that among 747 survivors who answered annual questionnaires, somatic symptoms, especially eye symptoms, affected 60 to 80 percent and had not decreased.