When choosing a fire protection system, it’s important to understand the options available and what’s recommended for your building. Fire extinguishers come in many forms. The difference lies in how each is designed to extinguish fire and the type of fires they are used for. We’ll take a look at the type of fire extinguishers available in the market below.
Water and foam
These types of fire extinguishers are designed to put off fire by separating the oxygen element from other elements. They are recommended for Class A fires only. When used in a Class B or C fire, a water and foam extinguisher can spread the fire or cause a shock hazard.
Carbon dioxide extinguishers
These fire extinguishers contain carbon dioxide in liquid form. When let off, the extinguisher releases this liquid into the air, which neutralizes the oxygen element of the fire triangle. This disables the fires ability to spread further. There are situations when it’s dangerous to use a carbon dioxide fire extinguisher. For instance, when used in a confined space, they can reduce the level of oxygen available to breathe and cause serious casualties. There’s also the risk of accidental discharge so this is not recommended in areas where there are children. Fire protection companies recommend this type of extinguisher for Class B and C fires only.
Dry chemical fire extinguishers
Dry chemical fire extinguishers contain foam or dry powder, which is compressed with nitrogen. When released, the extinguisher works by smothering the fire. The layer of foam or dry powder puts out the fire by creating a barrier between the oxygen element and the fuel element. This is what happens in Class A fires. Dry chemical extinguishers can also be used in Class B & C fires and they work in the same way by disrupting the chemical reaction in the fire triangle.
Wet chemical fire extinguishers
These extinguishers were mainly developed to help put off fires in commercial kitchens. Not all extinguishers were designed to put off big cooking fires. Some present the risk of burns because the pressure can cause the oil to jet out, resulting in serious harm. Wet chemical fire extinguishers are made up of a solution of potassium, which cools the fire and reduces the temperature then stops it from spreading or splashing. The potassium also reacts with the hot oils creating a barrier between the fat and oil.
Clean agent extinguishers
These are waterless fire extinguishing systems, often used to put off fires in office buildings because they are designed to deploy immediately without causing damage to important assets like electronics. They work by releasing Halogen and halocarbon agents, which interrupt the chemical reaction and remove heat from the fire triangle. They are used for Class A, B and C fires.
Dry powder extinguishers
These extinguishers, which are only used in Class D or combustible metal fires, put off fire by separating the fuel from the oxygen or removing the heat element in the fire triangle.
Water mist extinguishers
These extinguishers are used for Class A fires especially in situations where contamination is a problem. They work by removing the heat element of the fire triangle.
Cartridge-operated dry chemical extinguishers
These extinguishers put off fire by interrupting the chemical reaction of the fire triangle. A multipurpose dry chemical extinguisher can be used on Class A, B and C fires.