How to Choose the Right Fire Extinguisher.

Choosing the correct kind of fire extinguishers on the worksite is an integral aspect of fire safety. There are several types of portable fire extinguishers, each of which uses a different extinguishing agent to put out a fire. There are five main fire classifications in the United States: A, B, C, D, and K. The type of fire that ignites will decide how specialized personnel react to extinguish the fire. Keep in mind that various kinds of extinguishers are intended to combat different types of fire. The fire triangle consists of three elements: carbon, heat, and oxygen, and when these three elements combine, the resulting chemical reaction will create a fire. The trick to extinguishing a fire is to destroy at least one of the fire’s components, which is what portable fire extinguishers are intended to do.

Fire extinguishers are categorized according to the kind of fire they are meant to put out. They may be labeled with letters such as A, ABC, BC, D, or K to indicate the kind of fire they are intended to combat. It is vital for all companies and employers to train employees regarding fire extinguishers. All workers and employees should have information related to all types of fire extinguishers so that they may be prepared in case of emergency. According to OSHA rules and guidelines, a Portable fire extinguisher must be provided to employees at every office 1910.157(d) of the Occupational Safety and Health Act. The most popular kind of portable fire extinguisher for use at work and at home is the multi-purpose dry chemical fire extinguisher.

Fire extinguisher labels.

Dry chemical fire extinguishers

 Dry chemical extinguishers put out the fire by interfering with the fire triangle’s chemical reaction. To put out a flame, this extinguishing agent forms a buffer between oxygen and gasoline. Dry chemical fire extinguishers, which are usually graded BC or ABC, can be used on two or three different classes of fire, making them very handy. These multi-purpose are usually red and weigh between five and twenty pounds. Since certain dry chemical fire extinguishers are only rated for Class B and C fires, it is critical to know which form (BC vs. ABC) is in the workplace.

Air-pressurized water (APW) fire extinguishers

Water is used by APW extinguishers to put out the fire by cooling the surface of the fuel and removing the heating part of the fire triangle. Detergents are often applied to the water in an APW extinguisher to create foam. APW extinguishers, which are filled with water and pressurized air, are massive silver canisters that stand about 2 to 3 feet tall and weigh about 25 pounds when loaded.

Red and White Fire Extinguisher Sign

Carbon dioxide Fire Extinguisher

Carbon dioxide fire extinguishers operate by eliminating the oxygen portion of the fire triangle as well as the heat with their extremely cold release. On Class B and C fires, a carbon dioxide formula may be used. Attempting to use a carbon dioxide fire extinguisher on a Class A fire is ineffective since the fire may begin to burn and has the ability to re-ignite after the extinguisher is turned off.

Wet Chemical Fire Extinguisher

The wet chemical fire extinguisher was designed for use in commercial kitchens to safely extinguish Class K flames. Wet chemical extinguishers act by cooling the burning oil and eliminating the heating portion of the fire triangle. Extinguishing agents, by forming a shield between the fuel and oxygen, aid in preventing re-ignition after the fire has been extinguished. Wet chemical extinguishers use a highly efficient spray to keep hot oil from splashing down on the individual. Any wet chemical can also be used on Class A fires, and the letters AK on the packaging mean that they can be used on both Class A and K fires.

Clean Agent Fire Extinguisher

The clean agent may be classified as multi-purpose BC or ABC to battle various forms of fires efficiently and cleanly. Clean agent fire extinguishers can be used in commercial facilities that have fragile or irreplaceable components and machinery that may be destroyed by a water, foam, carbon dioxide, or dry chemic fire extinguisher so it may not leave a trace upon evaporation.

Young Woman Using Fire Extinguisher To Put Out Fire From Oven At Home

Water Mist Fire Extinguisher

For sensitive or critical areas, a water mist can be seen as an alternative to a clean agent extinguisher, and most are rated for both Class A and Class C fires. The water mist extinguisher uses de-ionized water (which is non-conductive and non-toxic) to disperse water using a special spray nozzle, which releases the water in the form of a fine mist into the air. Water mist fire extinguishers operate by cooling the area and removing the fire triangle’s heat element. Water mist extinguishers, and the fact that they use water to extinguish a burn, do not inflict water loss or leave a trace.

Dry Powder Fire Extinguisher

A dry powder can only be used for Class D or combustible metal burns. The dry powder fire extinguisher works by smothering the burning material with a dry powder extinguishing agent, separating it from oxygen, and removing the heat. Dry chemical fire extinguishers should not be mistaken with dry powder fire extinguishers (rated D). Using a dry chemical extinguisher on a Class D fire will either increase the fire’s strength or render it ineffective.

Various types and different sizes of extinguishers.


Now that you’re more educated, you should look at your property’s extinguishers and confirm you have the kind of extinguisher you’d like in the event of a fire at your specific facility. Keep in mind that various types of extinguishers can be needed in different areas of the facility. However, getting the right equipment is not enough. The right equipment can malfunction or be misused if it is not properly maintained or if your employees are not properly trained. It is important to check the expiry date of the fire extinguisher. For detailed fire extinguisher safety and awareness please visit Osha Outreach Courses.