Keeping Your Home Cool during the Sweltering, Summer Months

Understanding Fire Extinguisher Ratings

by Anthony Graves

One key component of home fire safety is the fire extinguisher. Not all fire extinguishers are created equal in that they come in different sizes and can be designed to combat different kinds of fires. Thus, to choose an extinguisher for your home, you need to make sure that you understand how to read the label, and specifically the ratings on the label. 

Fire Extinguisher Ratings: The Letters

The first thing to understand about a fire extinguisher label is the meaning of the letters on the label. You should find the letters A, B and/or C in a prominent place on the label. These letters refer to the kind of fire that the extinguisher is designed to combat.

  • The designation A means the chemicals in the extinguisher are designed to put out wood, paper, cloth, and other solid household items.
  • The designation B means the extinguisher contains chemicals to put out flammable liquids.
  • The designation C on the label means that the chemicals in the extinguisher will not conduct electricity and thus can be used to combat an electrical fire.
  • If the label on an extinguisher displays all 3 letters then it is effective against all three types of fires described above. 

Fire Extinguisher Ratings: The Numbers

You should also see numbers next to the letters. For example, you might see a label with the following grouping 3-A:20-B:C. The number in front of the letter depicts how effective the extinguisher is against the fire designated by the letter. For example, a 3-A extinguisher is three times more effective against ordinary solid combustibles as compared to a 1-A extinguisher. You'll notice that no letter proceeds the letter C. Because a chemical either conducts electricity or not, no number is needed here. 


While the size of your extinguisher is not necessarily a rating, the size does effect how effective the extinguisher is against fires. You want an extinguisher that is large enough to combat the type of fire you are dealing with. If you have a fire on your stovetop, a 2-pound extinguisher should be large enough to put out the flames.

On the other hand, if you have a burning bucket of oily rags in your garage, you may want to go with a 5-lb or even a 10-lb extinguisher. Just remember that the larger the extinguisher is, the harder it is to maneuver, so make sure you buy an extinguisher that you can actually handle rather than one so large that you struggle to move it. 

If you have questions about what type of extinguisher you should have in your home, or how many you should have, visit resources like Making sure you have fire extinguishers on location can help you to stop a fire before it burns out of control, and you lose your home.