Conditions needed for fire:

• A combustible material 
• A specific temeprature 
• Some fuel( mostly oxygen) to aid the burning.

The presence of the above three elements together is called the “Fire triangle”. Each of these three elements have to be present to start a fire, and for the fire to continue.

Common Fire Extinguishers:

1. Water Based: These are most effective on class A fires ( solid fire) . On class B fires, these are mostly ineffective. On class C fires (electric fires), these should never be used, it would surely be fatal because water is a good conductor of electricity.

2. Foam Based Extinguisher: These are used mostly on class B fires( oil fire) .These should never be used on class C fire because the main constituent of foam being water-it can easily prove to be fatal on class C fire.

3. CO₂ Based: These are mostly used on class C fires ( electric fire). It can also be used on class A and class B fire.

4. CFC Based: These are mostly used on class A and class B fires. It can also be used on class D fires( fire that involves metal)

5. Dry Chemical Based: These are most commonly used type of extinguishers. It can be used on class A,B and C fire. Hence, it is popularly also called as ABC type extinguisher.