How to use a Fire Extinguisher – P.A.S.S.

Should a fire ever happen, it is important to have a fire extinguisher at the ready. But without any idea how to use it, it could be more dangerous to use the extinguisher than to just run the other way. The most important part to using a fire extinguisher is to only use it when it is safe to do so. If it is not safe to fight the fire, leave the area immediately and dial 9-1-1.

That means that you know how to use an extinguisher. It also means that you have a clear exit path in the event that you are unable to extinguish the flames, allowing you to escape. If there is any doubt about the escape path, whatsoever, evacuate the building immediately. Lastly, the fire needs to be small enough to be fought by a fire extinguisher, use your best judgement for that, but again, when in doubt, evacuate and wait for first responders.

All fire extinguishers have operating instructions printed on their label. Most of them list the order of operation with the PASS Method. This is the same method that we are going to explain in this article. It is important to be familiar with it and know it instinctively.


In order to use a fire extinguisher to fight a fire, you need to locate the closest one. Be familiar with the building and take a look at any extinguishers you walk past. Not only are you familiarizing yourself with their locations, but also are performing preventative maintenance. Fire Extinguishers rely on their charge, which is indicated by the pressure gauge. Should that be depleted (in the red), then there is a problem that needs to be addressed. In looking at the fire extinguishers regularly, you notice these things.

Using the correct extinguisher for the fire is also important, as an extinguisher can be ineffective, or worse become a hazard to the user. Being familiar with the different classes of fire and the appropriate fire extinguishers for them should be a priority.

Fire Extinguisher P.A.S.S. Method

The PASS Method was created to make it easy to remember how to use a fire extinguisher. Using an extinguisher really is quite easy, though in an emergency situation, even the simplest concepts can become difficult. After locating the closest extinguisher and removing it from its wall bracket or housing, you would follow the steps of PASS:

P.A.S.S is an easy way to remember how to use a Fire Extinguisher

Pull the Pin

All Fire Extinguishers have a safety pin installed in the handle. This prevents it from accidentally being activated. The pin should always pull to the left and be secured with a tamper seal. Should the seal be missing, it may indicate tampering and the extinguisher should be replaced with a known functional one. The Pin itself should be quite lose and only secured from sliding out by the tamper seal. Any other object, such as a Zip Tie in place of the tamper seal, or a nail instead of the Pin are prohibited. Replacing the Pin or the Seal with anything but the approved parts, can prevent the extinguisher from functioning.


Once you have the extinguisher at the ready, aim the nozzle towards the Base of the fire. Most fire extinguishers work by blanketing the fuel of the fire, or by cooling the fire. That’s why it is important that the base of the fire gets the most of the extinguishing agent.


Squeezing the trigger is the next step. When squeezing the trigger, make sure you are holding the nozzle firmly and are not covering the nozzle opening. Keep squeezing the handle for as long as the extinguisher is discharging. This ensures that all possible extinguishing agent is used. Note that the average extinguisher will only spray for about 10-25 seconds. That’s why it is important not to overestimate the extinguishers fire fighting capabilities.


When the fire extinguisher is discharging, sweep the nozzle across the base of the fire. By sweeping, you ensure that the base is evenly covered with the extinguishing agent. Start from a safe distance from the fire and move closer as the extinguisher fights the fire. Once the fire is extinguished, keep an eye on the area. Fires can re-ignite even after having been extinguished.

Deciding to Fight the Fire with a Fire Extinguisher

To reiterate, if you have any doubts about your ability to use a fire extinguisher or that you can be effective in fighting it – Evacuate the building immediately.

A fire extinguisher should only be used in the following scenario:

  • the fire is in its early, incipient stage
  • you have the right fire extinguisher for the class of fire
  • you have a safe exit path

If the fire extinguisher fully discharges prior to extinguishing the fire, exit immediately and do not continue fighting it, if it develops past its incipient stage. Your safety should always be at the forefront of every fire fighting decision you make.

Are All Fire Extinguishers Created Equal?

Hand Holding Fire Extinguisher Handle

Fire Extinguishers are around us all the time and we should always know where the nearest one is. All extinguishers, however, are not created equal. There are different sizes and different types of fire extinguishers intended to fight different classes of fires.

To be truly fire smart, the right fire extinguisher has to be installed in the right location. This will maximize the effectiveness of a fire extinguisher in the event of a fire.

Fire basics and why the type of fire matters

Fire Tetrahedron – Elements required for Fire

The theory of fire is based on what is called the Tetrahedron. It outlines the four elements required for a fire to be present. By removing one of these elements, the fire cannot continue and is thus extinguished. The four elements are:

  • Fuel
  • Heat
  • Oxygen
  • Chain Reaction

A fire extinguisher works on the principle that it will remove one or multiple of these elements and stop the fire in its tracks. There are different types of fuel for the fire and that is where the different classes of fire extinguishers come in. The reason for the different classes becomes quite obvious with the example of using a water extinguisher on an electrical fire. This will cause a hazard to the user.

There are five main classes of fires, which we will discuss further in this article.There is a specific extinguisher for each class and some cover multiple classes. The classes are:

  • Class A – Ordinary Combustibles, such as paper or wood
  • Class B – Flammable Liquids, such as gasoline
  • Class C – Live Electrical Fire – Serves as the cause for a Class A or B fire. If the electrical is removed, it is no longer a Class C fire.
  • Class D – Combustible Metals, such as Magnesium or Sodium
  • Class K – Grease Fires

Types of Fire Extinguishers

With a basic understanding of fires and why different fire extinguishers are necessary, let’s discuss the six main types of extinguishers and their uses:

A-B-C Fire Extinguishers

ABC Fire Extinguishers contain a fine powder, commonly mono-ammonium phosphate. It is the most common fire extinguisher found in just about every building. This type of extinguisher has the advantage that it is highly versatile as it can be used on Class A, B and C fires. The principle and ABC extinguisher operates under is that it blankets the fire and aims to starve the fire of its Oxygen. The powder is not an electrical conductor and can effectively interrupt the chain reaction in a gas or liquid fire.

Wet Chemical Fire Extinguishers

Wet Chemical Fire Extinguishers primarily fight Class K or grease fires. The chemical inside of a Class K extinguisher is a solution primarily composed of potassium, which fights the fire in two separate ways. The chemical will act to cool the fire initially, starving the fire of the heat component. Upon contact with the grease or cooking medium, the chemical starts to foam and blankets the area, which is intended to prevent re-ignition of the fire. While we chemical extinguishers are your perfect choice for a kitchen, they can also be effective on Class A fires.

Water-mist Fire Extinguishers

Water Mist Fire Extinguishers are the newest type of fire extinguisher. These extinguishers work across almost all classes of fire. When used, the water fire extinguisher releases a fine mist of water, which attacks several elements of the fire tetrahedron.

First, it starves the first of oxygen, as the fine water particles take up space and decrease the oxygen levels near the fire. Second, the water will cool the fire and affect the heat component, as water naturally does. What is unique about water extinguishers is that the water generally has had all minerals removed (de-ionized), which means it can also be used on electrical fires, as it does not act as a conductor. That means that water fire extinguishers are effective for Class A, B, C and K fires.

Clean Agent Fire Extinguishers

Clean agents are a type of gas fire extinguisher. The extinguisher contains a liquid, which, when discharged, will convert to its gaseous form. The gas is non-conductive, leaves no residue and dissipates very quickly which makes it Eco-friendly. The gas used is usually a Hydrochlorofluorocarbon, marketed as Halotron. The extinguishing agent reduces the oxygen levels and impedes the chain reaction of the fire. As it doesn’t leave any residue, it is ideal for server and electrical equipment or Class B and C fires.

Carbon Dioxide Fire Extinguishers

A CO2 Extinguisher is another type of clean agent extinguisher, as it does not leave any residue. The extinguisher disperses the oxygen from the fire and replaces it with the CO2 contained within. This effectively suffocates the fire, making it the perfect choice for Class B and C fires.

Foam Fire Extinguishers

A foam extinguisher contains a liquid, which foams and expands upon contact with the air. The foam then blankets the fire, which starves the fire of its fuel. The foam has a cooling effect as well, as it does contain some water. Foam extinguishers can be used on Class A and are excellent for Class B fires, though lose their effectiveness for gaseous fires.

Are you protected?

Now that you have more information about the types of fire extinguisher that are out there, take a look around and see what fire extinguishers your business has. Make sure you have a fire extinguisher for every hazard class that may be present in your facility.

Another important aspect to fire extinguishers and fire safety is getting the extinguishers maintained and inspected, and ensuring everyone is properly trained on how to use a fire extinguisher.

Nexus Fire & Safety can assist with fire extinguisher layout and ensuring the right extinguisher for the hazard is present. Our team is fully certified and can provide training for your staff. We are also equipped to maintain and test your fire extinguishers, ensuring they are ready for use, should you need them.