Types Of Fire Extinguishers

A fire extinguisher is a special device used to put out small fires. This active fire protection device is not used, however to put out out-of-control fires, but is only used for the purpose of putting out small level fires.

A fire extinguisher, typically, consists of a hand-held cylindrical pressure vessel. This vessel contains a substance which, when discharged, can extinguish a fire.

There are two main types of agents that can be used: dry chemicals or liquid chemicals. The dry chemical fire extinguishers include nitrogen or other cases while the liquid type extinguishers include water and other liquid reagents that can put out a small fire.

There are basically five types of fire extinguishers that are made exclusively for different types of fires, there fore, talking about the types of fire extinguishers, we first must look at the different types of fires on which these fire extinguishers are based on.

Following are the different classes of fires:

Class A Fires

These fires are caught on solid substances such as paper, wood, plastic etc

Class B Fires

These fires are caused by the flammable liquids such as paraffin, petrol, oil etc.

Class C Fires

Class C fires are due to flammable gases such as propane, butane, methane etc 

Class D Fires

These are caused by metals such as aluminum, magnesium, potassium or sodium.

Class E Fires

These fires involve electrical appliances such as outlets, circuit breakers, or wiring.

As said a fire extinguisher is made exclusively for any of the above classes of fires. These different types of fire extinguishers contain special agents that can only extinguish the fire for which they are made. Following are the five main types of fire extinguishers:

Water Fire Extinguishers

The water fire extinguisher is the cheapest and the most widely used fire extinguisher. This type of fire extinguisher is used typically for Class A fires and is filled with water, pressurized with oxygen. This fire extinguisher works only for the type A fire extinguishers and are not suitable for type B, C, D and E fires.

Foam Fire Extinguishers

The foam fire extinguishers are used to put out the fires of class A and B, and are more expensive and versatile than the water fire extinguishers.

They are filled with foam and are pressurized with nitrogen. They are only used for A and B type fires and can not be used on type E fires that involve electricity.

Dry Powder Fire Extinguishers

A dry powder fire extinguisher is a multi-purpose extinguisher used for Class A, B and C fires.

It is pressurized with nitrogen but special powders are also available for Class D metal fires. This versatile fire extinguisher is expensive and much effective.

However certain precautions must be taken while using this extinguisher. For example if you are using it for gas type fires then you must first cut out the gas supply.

Also this fire extinguisher leaves a sticky or corrosive residue that can be damage the surface on which it has been sprayed.

The CO2 Fire Extinguishers

The carbon dioxide fire extinguisher is used to extinguish electrical fires, but it can also be used to extinguish Class B and C fires. This highly pressurized extinguisher contains carbon dioxide as its name suggest.

The best thing about these extinguishers is that they do not leave a harmful residue and does not corrode the material it is sprayed on. But on the negative side, it has no post fire security i.e. if it is not able to displace enough oxygen, the fire could re-ignite.

Metal Fire Extinguishers

These fire extinguishers are exclusively to extinguish the class D fires. They are not suitable for electrical type fires. But they must be used at the very initial stage of the fire because metal fires can erupt quickly.

Fire extinguishers are a great invention in terms of wiping out the small level fires.

A fire is highly contagious and can spread within a short span of time once made to contact a flammable substance.

A fire extinguisher cuts out the fire before it can reach the stage of rapid eruption that can cause a major destruction.