How to operate a fire extinguisher diagram

The most common form of fire fighting equipment are extinguishers.

There are 4 classes of fires, depending on what kind of fuel is fuelling the fire.

Class A Fires – ordinary combustible materials
Class B Fires – flammable liquids or liquefiable solids
Class C Fires – gases.
Class D Fires – burning metals.

There are different extinguishers for different classes of fires:

* Water (Colour Code: Red)
Suitable for Class A fires. These extinguishers cannot be used on live electrical fire. However, they can be safely used on burning electrical equipment once the electrical supply has been isolated.

* Foam (Colour Code: Cream)
Different foams can be suitable for different classes of fires. Some contain a water-based foam and are not suitable for use on live electrical equipment. Usually foam extinguishers can be used either on Class A or on Class A & B fires.

* Powder (Colour Code: Blue)
Suitable for Class A fires – and some also suitable for Class B. Powder extinguishers not always penetrate inside spaces and it causes clogging of machinery, which might otherwise be re-usable.

* Special dry powders can be used on Class D fires.

* Carbon Dioxide (Colour Code: Black)
Suitable for Class B fires and safe and clean if used on live electrical equipment. CO2 is an asphyxiate, and great care must be taken in its use.

Vaporising Liquids (Colour Code: Green)
Suitable for Class B fires and on live electrical equipment.

Halona extinguishers should be replaced wherever possible. They are of an old kind and should not be used.
This type of extinguisher also produces asphyxiate gases and the same care is needed as for CO2.

This text was inspired by a text found at Fire Safety and Security Management from India