Common Fire Extinguisher Types

08/27/2018

Choosing the right type of fire extinguisher can be a confusing task because of the many fire extinguisher types available. You should be very mindful when you choose a fire extinguisher because each type is intended to put out a fire caused by different materials.

Fire extinguishers are categorized into several classes to which they are used for. These extinguishers also have a numerical rating for their use. Class A extinguishers are used for ordinary combustible materials. These include paper, cardboard, plastics, and wood. The numerical rating found on this type of extinguisher shows the amount of water it can hold and the amount of fire it can extinguish. Class B fire extinguishers are specially formulated to put out fires which care caused by flammable and combustible liquids like oil, gasoline, grease, and kerosene. The numerical rating for Class B extinguisher indicates the area of fire in square feet it can extinguish.

Class C fire extinguishers put out fires which involve electrical equipment, including appliances, outlets, wirings, and circuit breakers. When dealing with a class C fire, it is important to remember that water should not be used to extinguish it because the risk of an electric shock is great. Class C extinguishers have extinguishing agents that are non-conducive and they do not have a numerical rating. One of the most common fire extinguisher types are those found in a chemical laboratory. This type is categorized as Class D fire extinguisher and is for fires involving combustible materials like sodium, potassium, magnesium, and titanium. Similar to Class C extinguishers, Class D extinguishers do not have a numerical rating and are to be used exclusively for Class D fires.

Aside from these classifications, fire extinguishers are also categorized according to the extinguishing agent used. Water extinguisher, also known as air-pressurized water extinguisher, is only suitable for class A fires only. Using a water extinguisher on a Class C or Class D fire will only make the fire bigger so be careful when identifying the kind of fire before using a particular extinguisher. A water fire extinguisher is filled with water and is pressurized with oxygen, thus can be very dangerous in the wrong type of situation. Only fight a fire with a water extinguisher if you are sure that the fire is caused by ordinary combustible materials only.

Dry chemical extinguisher is another type of fire extinguisher and has a variety of types. This type of fire extinguisher is suitable for a combination of class A, B, and C fires. Dry chemical extinguishers can be filled with foam or powder, pressurized with nitrogen. The regular type of dry chemical extinguisher is the one which is filled with sodium bicarbonate and potassium bicarbonate. This is called the BC extinguisher. The BC variety leaves a mildly corrosive residue which needs to be cleaned immediately to prevent further damage.

Another variety is the ABC extinguisher which is a multipurpose dry chemical extinguisher filled with monoammonium phosphate which is damaging to electrical appliances. Compared to CO2 extinguishers, dry chemical extinguishers have the advantage because they leave a non-flammable residue on the extinguished materials.

On the other hand, CO2 extinguishers have the advantage over dry chemical extinguisher such that they don't leave a harmful residue on an electronic device. These extinguishers contain carbon dioxide and are highly pressurized to extinguish a fire