An anti-intruder defense used aboard starships and Federation facilities; a concentration of 70 parts per million is more than enough to render humanoids unconscious. Aboard the U.S.S. Enterprise NCC-1701-D, Captain Picard had Data flood the gas throughout the already cleared bays on Deck 38 when Roga Danar was suspected in a cargo bay there. Commander Riker suggested using it on their alien-possessed shipmates and hostages in Ten-Forward, but Chief Engineer LaForge points out the gas wouldn't work on Data. It has also been known as "anastazine."