A fire extinguisher is an active fire protection device used to control or extinguish a small fires in case of emergency. This can not be used for large or out-of-control fire. A fire extinguisher is a hand held portable types of a cylindrical shaped device which contains chemical / gas / agents which can be discharged to extinguish the fire. Stored pressure and cartridge operated are main two types of fire extinguishers. In stored pressure type of fire extinguisher, the expellant is stored in the same chamber as the fire fighting agent itself. With dry chemical types of extinguisher, Nitrogen while in water and foam types , Air is used as an expellant. Stored pressure type type of fire extinguisher are most commonly used in the industries. Cartridge operated extinguisher contain the expellant in a separate cartridge which is punctured prior to discharge. They have advantage of simple & frequent recharge in a reasonable time once it is discharged. These fire extinguishers use compressed nitrogen gas instead of nitrogen, how ever nitrogen cartridge are used on low temperature models.