Residential Fire Extinguishers - How They Work and Why They Matter


Fire extinguishers are a small but often overlooked add-on to your home’s fire safety devices. Many of the 300,000+ annual home fires start off small in origin and can often be put out quickly using fire extinguishers. Fire extinguishers save lives and property every day and are a simple addition to your home. This blog post will talk about how to use them, where to place them, and why they are needed.

Only attempt to extinguish a fire once you’ve made sure that everyone else has left your home, and that the fire department/911 has been called. Property is always worth less than lives. Never fight a fire that isn’t confined to one area, as it can quickly spread around you. If the room begins to fill with enough smoke that breathing becomes difficult, exit immediately. 

Types of fire extinguishers

There are 3 typical types of residential fire extinguishers: Class A, Class B, and Class C. Class A are rated for trash, wood, and paper. Class B are rated for liquids and gasses. Class C are rated for electrical sources. It’s crucial that you understand which fire extinguisher to use, as a water based extinguisher against an electrical fire could give you a nasty shock.

Typically, you’ll see numbers in extinguisher specifications, like 3-A: 40-B:C. These numbers refer to the firefighting capacity, as a 10-B unit will put out twice as much liquid as a 5-B unit. We recommend a 3-A:40-B:C extinguisher for your general home needs. This extinguisher combines the 3 classes as a multipurpose extinguisher and has more than enough capacity to tackle your fire needs. If this unit is too cumbersome, a 2A:10-B:C unit will get the job done as well. A class B:C extinguisher is sometimes used for kitchens, which should be rated 10-B:C or higher. 

How do fire extinguishers work? 

The three components of any fire are oxygen, heat, and fuel. Most fire extinguishers like Carbon Dioxide, dry powder, and foam extinguishers work by separating the oxygen from the fuel or smothering the flame by creating a barrier between the two. Water-based extinguishers mainly work by removing heat from the fire, with the ensuing steam cutting off oxygen.

To use a fire extinguisher, start by pulling the metal pin out from the top portion of the extinguisher. Aim the black nozzle low near the base of the fire and slowly and evenly squeeze the lever, sweeping the nozzle from side to side, making sure that the fire is completely extinguished before stopping. 

Where should fire extinguishers be placed?

Fire extinguishers should always be placed in an accessible location and not blocked off by storage and equipment. The top of the extinguisher should not be more than 5 feet off the floor, and no less than 4 inches. It should be placed in an area in which it won't be damaged by walking traffic and placed so that the labels face outwards. If mounting brackets are included, using them is an easier way to get the fire extinguisher set up.

There should be at least one fire extinguisher on each level of your home and one near every source of heat. It’s good practice to keep extra fire extinguishers around bedrooms, garages, and kitchens, as those are common sources of fires.

It’s important to remember that having a fire escape plan and alarm systems are your first defense against any fire. Fire extinguishers add an extra layer of security when you know how to use them correctly. Bundl Home includes fire alarm testing and fire extinguisher inspection as part of our seasonal maintenance handyperson visits - learn more here.