Let’s start at the base and understand all the classes of the abc fire extinguisher. The class A is used for the purpose of trash, wood and paper; the class B is used for the purpose of liquids and gases and lastly the class C is used for the energized electrical sources. This type of fire extinguisher is used for multiple purposes such as fires which involve ordinary or regular combustible, flammable liquids and energized electrical equipment. CO2 fire extinguisher is different than this as they are only used to put of class B type of fires and sometimes are even used to fight class C type of fires but are not appropriate for class A fires.
How it works?
In this type of fire extinguisher the ABC powder that is used is often made up of ammonium or mono-ammonium phosphate which is mixed with other powders so that it can improve the flow or add bulk. ABC powder is many a times referred to as the general purpose or multi-purpose extinguisher powder and is capable to fight class A, B and C fires, as the name suggests. On the other hand, the gas that is used in this powder is nitrogen gas which is filled with a yellow colored powder. The reason why nitrogen gas is used is so that it can pressurize the extinguisher. Monoammonium, which is added as the powder is used in the maximum quantity in the preparation of this gas.