Learn The 5 Classes of Fires And Which Fire Extinguisher To Use

Posted On: October 30th, 2019

All fires are not the same, and so you will need to know how to handle each type. If you use the wrong fire extinguisher agent, you can even make it worse. That’s why it’s so important that you know and can recognize the five different classes of fires. Here’s what you need to know, and how you can put these fires out safely.


1. Class A Fires: Combustible Materials

The first type of fire you need to be aware of is the Class A fire, which is the one you’ll most commonly think of when you think of fire. These fires are started by solid combustibles. This includes paper, wood, clothing, trash, plastic, and so on.

In many cases you’ll actually start a Class A fire intentionally, for example when lighting a wood stove or a barbecue. If that fire gets out of control, or a Class A fire breaks out without your guidance, you’ll need to handle it quickly. These fires are ones that can be handled with water. Using a water or foam fire extinguisher will be just the thing to put it out. Water will remove oxygen and the heat source to the fire, stopping it in its tracks.


2. Class B Fires: Flammable Liquids and/or Gases

The next fire type you need to be aware of is the ones started by flammable liquids. These include alcohols, oil, gasoline, and paint. These fires are dangerous as they can happen anywhere these liquids are used or stored. As such, if you have these liquids stored somewhere you need to be prepared in case they do ignite.

Unlike Class A fires, you should never use water on these fires. Water will actually help the fire spread, as it will spread the liquid that’s fueling it. Instead, you need a fire extinguisher that uses foam, powder, or carbon dioxide. These will cut off the oxygen supply to stop the fire from spreading. Having one of these to hand near any flammable liquids is a must.


3. Class C Fires: Electrical and/or Energized Equipment

Any home or business owner must be prepared for electrical fires, as they’re common and can cause serious damage. An electrical fire will break out if there are frayed wires, old wiring in the walls, faulty appliances, overloaded extension leads, and so on. It’s important to take good care of your electronics to avoid a fire.

If an electrical fire does break out, then it’s best to put it out with a carbon dioxide or dry powder fire extinguisher. Again, it’s vital to avoid water in these situations. Water will conduct electricity, making the situation more dangerous all round.

Be aware that if the power is cut to the device causing the fire, it can then become a Class A fire. In that case, you can use Class A methods of putting out a fire.


4. Class D Fires: Flammable Metals

This is a rare type of fire, which happens when metals ignite. Usually, metals need to get to a very high temperature in order to catch fire, so you’re more likely to see these fires in industrial settings, rather than in your home. Metals such as magnesium, aluminum and sodium are able to ignite as they are alkali metals.

If you have a metal fire, the best way to put this out is to use a dry powder extinguisher only. Water or foam extinguishers will cause these kinds of fires to get worse, so be on your guard.


5. Class F/K Fires: Cooking Oils and/or Fats

These fires are most commonly kitchen fires, as they involve cooking oils. Although they technically are liquid fires, they come under their own classification as they’re a common house fire cause.

A fire often happens if a pan is left on the stove for too long unattended, and the oil ignites. If that happens to you, turn off the heat and move the fire away fro the heat source if possible. Then to put it out, you’ll need a wet chemical extinguisher to do so. Just like with regular liquid fires, you should never use water as this will cause the fire to spread.

All commercial kitchens should have the right type of fire extinguisher to hand, in case a fire breaks out. They’re also very useful to have in your home kitchen, too.


How to Choose and Use the Right Fire Extinguisher

As you’ve seen, all these fires need the right fire extinguisher agent to be put out. If you’ve never used one before, there’s no need to worry. All you need to do is remember the PASS system, and you’ll be able to do so:

Pull the pin.

Aim the nozzle from a safe distance at the base of the fire.

Squeeze the handle slowly.

Sweep the nozzle from side to side until the fire is out.

Remember this acronym, and you have everything you need to fight a fire.


When You Can’t Extinguish a Fire

There will be times when you won’t be able to tackle a fire yourself. If it has become too large, or you’re not confident about tackling it, instead raise the alarm. Yell and pull any alarm pulls that are near you, to alert others. Then, get out of the building.

Stay low to the ground, use stairs rather than elevators, and feel any door with the back of your hand before you open it. If it doesn’t feel cool to the touch, it will not be safe to open. As soon as you’re out, call 911 to get the emergency services to your location.

Now you know there are several types of fire, and they are all tackled in different ways. Having the right type of extinguisher is crucial, as some will make fires worse. If you’re not sure of the source of the fire or can’t tackle it, instead evacuate and call for help instead.

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