Fire extinguishers are an active fire protection device used to extinguish or control small fires, though they are ineffective for out-of-control fires. Typically, fire extinguishers are composed of a hand-held cylindrical pressure vessel containing an agent (such as nitrogen or carbon dioxide) that can be used to extinguish a fire.
Because of safety regulations, public areas or military bases are required to have at least one fire extinguisher on hand in the event of a fire.
While Venom Snake and Ishmael were trying to escape XOF forces invading the Dhekelia Memorial Hospital at Cyprus, a blaze forced Snake to shoot a fire extinguisher to halt the advance of the blaze.
During the 2007 Tanker Incident, after stumbling upon a Semtex/infrared sensor trap set up by the Gurlukovich Mercenaries, Solid Snake at Otacon's suggestion shot a nearby fire extinguisher to be able to sight the otherwise invisible sensors.
Although technically not a fire extinguisher, the FOXHOUND agent Raiden made use of the coolant spray in a similar manner to a fire extinguisher when escorting Emma Emmerich to the Core 1 server room to extinguish some fires caused by the fighting on the Big Shell during the 2009 Manhattan Incident.
Behind the scenes
Fire extinguishers first appeared in Metal Gear Solid 2: Sons of Liberty, and in other games in the Metal Gear series, where they acted as a non-lethal trap by shooting the fire extinguishers to let off an explosion of smoke to deter any pursuers.
Although fire extinguishers themselves cannot be used as an accessible item in the actual game, Metal Gear Solid 2 did have the Coolant spray, which served a similar purpose late in the game. The Trial edition demo for the game did apparently have a fire extinguisher as an actual weapon.
In Metal Gear Acid 2, shooting a fire extinguisher will cause it to explode and release its content, causing some damage and temporarily blinding anyone near it by coating them with the extinguisher's content, victims becoming unable to see enemies and the cards on their hand. A target covered by the extinguisher's content will not be affected by the "burning" status ailment.