Industry
Fact-checked

At AboutMechanics, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What are the Different Kinds of Fire Extinguishers?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

Fire extinguishers are highly recommended to have around the home, office, and car. In a fire, quick thinking combined with rapid application of a fire extinguisher can prevent the fire from spreading, greatly reduce damage, and potentially save lives. However, different types of fires call for different types of fire extinguishers, and using the wrong fire extinguisher can be dangerous. At best, you may actually cause the fire to spread, and you could become seriously injured or lose your life. Fortunately, fire extinguishers are rated by fire class, to make it easy to figure out whether or not an individual fire extinguisher is appropriate for the task at hand.

The most basic type of fire extinguisher is a Class A extinguisher. When a fire is categorized as a Class A, it involves “ordinary combustibles,” such as paper, wood, cardboard, and simple plastics. Class A fire extinguishers are often just filled with water under high pressure, to choke the fire by cutting off its supply of oxygen. Typically, Class A fire extinguishers indicate how much pressurized water they hold.

Class B fire extinguishers are used to put out gasoline fires.
Class B fire extinguishers are used to put out gasoline fires.

A Class B fire is a fire which involves flammable combustibles, such as grease, oil, and gasoline. Spreading water on a Class B fire can cause it to grow even larger, by scattering the combustible around the area. Class B fire extinguishers are filled with a chemical mixture which is designed to put the fire out safely, and their packaging typically shows how many square feet the fire extinguisher can put out. This number will vary, depending on the intensity of the fire and materials involved. A subclass of a Class B fire, the K fire, is a kitchen fire, which can pose a serious problem in a commercial kitchen.

Class C fire extinguishers are designed for electrical fires.
Class C fire extinguishers are designed for electrical fires.

Class C fire extinguishers are designed for electrical fires. They contain non-conductive flame retardants to smother the fire. It is extremely dangerous to use water on a Class C fire, as you may severely shock or kill yourself. Class C fire extinguishers should be kept in the car and in home offices and other areas with large amounts of electrical equipment.

Fire extinguishers are coded by letter based on the type of fire they can fight.
Fire extinguishers are coded by letter based on the type of fire they can fight.

The final type of fire, a Class D, is a fire involving flammable metals. Typically, a Class D fire will only be encountered in a manufacturing or laboratory setting. While many companies sell combination fire extinguishers such as ABC or BC extinguishers, a Class D extinguisher is never combined with others. These extinguishers use dry powder, rather than the dry chemicals used in B and C fires.

Class A fire extinguishers are typically filled with pressurized water and are suitable for "ordinary combustibles."
Class A fire extinguishers are typically filled with pressurized water and are suitable for "ordinary combustibles."

Fire extinguishers can lose pressure or become damaged. They should be inspected regularly, and many fire departments offer this service free of charge. If a fire extinguisher has been used, it can be recharged at a fire department with the appropriate material. Always make sure that your fire extinguishers are readily available in case of emergency, and make sure that all employees and family members know the location of the fire extinguisher, along with the meaning of the ratings.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AboutMechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AboutMechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

Lostnfound

My only problem with fire extinguishers is that most of them take too many steps to operate. You have to pull the pin, detach the hose and then spray. If you need to put out a fire, you don't have time to do everything in the order listed. Manufacturers should think about streamlining the prep process, so that it takes just a couple of seconds to get the extinguisher ready, as opposed to a minute or so. That's a lot of time when you're dealing with a fire.

Post your comments
Login:
Forgot password?
Register:
    • Class B fire extinguishers are used to put out gasoline fires.
      By: sint
      Class B fire extinguishers are used to put out gasoline fires.
    • Class C fire extinguishers are designed for electrical fires.
      By: ia_64
      Class C fire extinguishers are designed for electrical fires.
    • Fire extinguishers are coded by letter based on the type of fire they can fight.
      By: isonphoto
      Fire extinguishers are coded by letter based on the type of fire they can fight.
    • Class A fire extinguishers are typically filled with pressurized water and are suitable for "ordinary combustibles."
      By: marilyn barbone
      Class A fire extinguishers are typically filled with pressurized water and are suitable for "ordinary combustibles."
    • Class B fire extinguishers can be used to put out grease or oil fires.
      By: hartphotography
      Class B fire extinguishers can be used to put out grease or oil fires.