Overview
It is very important to choose the proper fire extinguisher. Extinguishing agents have differing attributes, which make
them more or less appropriate for use, depending on the class of fire, and the setting in which they will be used. Some
agents can be used on more than one class of fire, and some have very specialized characteristics that make them
particularly suitable for a specific class of fire situation.
Water or Foam Fire Extinguishers extinguish the fire by taking away the heat element of the fire triangle. Foam agents also separate the oxygen element from the other elements. Water extinguishers are suitable for Class A fires only – they should not be used on Class B or C fires. The discharge stream could spread the flammable liquid in a Class B fire or could create a shock hazard on a Class C fire. Foam extinguishers can be used on Class A and B fires only. They are not for use on Class C fires due to shock hazard.
Regular Dry Chemical (Class B, C) Fire Extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle. Today’s most widely used type of fire extinguisher is the multipurpose dry chemical extinguisher that is effective on Class A, B, and C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires. Ordinary dry chemical extinguishers are for Class B and C fires only. It is important to use the correct extinguisher for the type of fuel. Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully. They are suitable for garages and laboratories.
Carbon Dioxide Fire Extinguishers extinguish the fire by taking away the oxygen element of the fire triangle and also by removing the heat with a very cold discharge. CO2 fire extinguishers are ideal for areas where contamination and clean-up are a concern. CO2 extinguishers can be used on Class B and C fires. They are usually ineffective on Class A fires.
Halogenated or Clean Agent Fire Extinguishers include the halon agents as well as the newer and less ozone depleting halocarbon agents. They extinguish the fire by interrupting the chemical reaction of the fire triangle. Clean agent extinguishers are primarily for Class B and C fires. Some larger clean agent extinguishers can be used on Class A, B, and C fires. Halogenated or Clean Agent Fire Extinguishers are suitable for use in computer rooms, telecommunications and high-tech clean rooms.
Type K Wet Chemical Fire Extinguishers use a new agent that extinguishes the fire by removing the heat of the fire triangle and prevents re-ignition by creating a barrier between the oxygen and fuel elements. These type of extinguishers were developed for modern, high efficiency deep fat fryers in commercial cooking operations. Type K Wet Chemical Fire Extinguishers are typically required in commercial kitchens.
Cartridge Operated Dry Chemical Fire Extinguishers extinguish the fire primarily by interrupting the chemical reaction of the fire triangle. Like the stored pressure dry chemical extinguishers, the multipurpose dry chemical is effective on Class A, B & C fires. This agent also works by creating a barrier between the oxygen element and the fuel element on Class A fires. Ordinary dry chemical extinguishers are for Class B or C fires only. It is important to use the correct extinguisher for the type of fuel. Using the incorrect agent can allow the fire to re-ignite after apparently being extinguished successfully. They are suitable for garages and laboratories. They are used in high-hazard areas where fast, effective fire protection is needed, such as mining, utilities, forestry, transportation, petroleum and heavy industry.
Dry Powder Extinguishers are similar to dry chemical except that they extinguish the fire by separating the fuel from the oxygen element or by removing the heat element of the fire triangle. Dry Powder Extinguishers are for Class D or combustible metal fires only. They are ineffective on all other classes of fires. This type of extinguisher is useful for petroleum plants, airports, large storage facilities, construction sites and equipment depots.
Wheeled Deluxe Fire Extinguishers are typically useful for petroleum plants, airports, large storage facilities, construction sites and equipment depots.