Fire Extinguishers

A fire extinguisher is an active fire protection device used to extinguish or control small fires, often in emergency situations.

Typically, a fire extinguisher consists of a hand-held cylindrical pressure vessel containing an agent which can be discharged to extinguish a fire.

There are two operation types of fire extinguishers: 

i. Stored pressure 

ii. Cartridge-operated 

Stored Pressure 

In stored pressure units, the expellant is stored in the same chamber as the fire fighting agent itself. Depending on the agent used, different propellants are used. With dry chemical extinguishers, nitrogen is typically used; water and foam extinguishers typically use air. 

Cartridge Operated 

Cartridge-operated extinguishers contain the expellant gas in a separate cartridge that is punctured prior to discharge, exposing the propellant to the extinguishing agent. This type is not as common, used primarily in areas such as industrial facilities, where they receive higher-than-average use.

Suitable Fire Extinguishers For Fire Classes

Foam - Suitable for Class A and Class B fires, with limited effectiveness

for Class F fires. Common used Agent: Aqueous Film Foaming Foam (AFFF)

Powder - These extinguishers are suitable for Class A, Class B, Class C and Class E fires.

Common used Agent: Mono-ammonium Phosphate 

Carbon Dioxide (CO2) -  Suitable for Class E fires. Has limited effectiveness on Class A and Class B fires.

Use of Fire Extinguishers