PASS Fire Safety: How to Use a Fire Extinguisher

Fire safety is a topic that is often overlooked until it’s too late. We all know the importance of fire safety, but how many of us truly take the time to ensure that we’re prepared for the worst-case scenario? 

Whether you’re working from home in your pajamas or dining at your favorite restaurant, a fire can strike anywhere, anytime. So in this article, we’re going to tell you about PASS fire safety to ensure you’re prepared should a flame ignite.

To understand and effectively employ the PASS technique, you need to know the types of fire classes and fire extinguishers first.

The five fire classes

Whichever class of fire you encounter, you’ll use the PASS fire safety method to tackle the flames. Let’s talk about how each of the five fire classes ignites and where they each typically occur. 

Class A

Class A fires are fueled by everyday combustibles such as wood, paper, and cloth. They can start anywhere from your backyard Fourth of July BBQ to the break room where you eat lunch at work. Likewise, they can re-ignite easily if not fully put out by the proper fire extinguisher.

Class B

Class B fires are started by flammable liquids and gasses, such as gasoline, propane, and oil, and can spread– quite literally– like wildfire. They’re most likely to occur in industrial settings but can still ignite in commercial and residential properties.

Class C

A Class C fire ignites from energized electrical equipment. For example, fuse boxes, appliances, computers, and faulty wiring can all trigger a Class C fire. Likewise, these flames typically start when an electrical device malfunctions or overheats, causing a spark that ignites nearby combustible materials.

Pro-tip! Before putting out a Class C blaze with the appropriate Class C fire extinguisher, make sure to cut off the electrical power source first.

Class D

Class D fires are a rare but serious type of fire that can occur when combustible metals, such as magnesium, titanium, or sodium, ignite. These flames can occur in a variety of industrial settings where combustible metals are present. 

For example, a Class D fire could ignite in manufacturing plants, laboratories, and workshops. So, unless you’ve got a ‘Breaking Bad’ lab running in your basement, you won’t see a Class D blaze in your home.

Class K

Nicknamed “restaurant fires,” a Class K fire typically starts in commercial kitchens when hot cooking oil, grease, or fat ignites, creating a sizzling and volatile inferno. Thus, these kitchen blazes are often triggered by overheated cooking appliances, deep fryers, human error, or lack of proper maintenance.

Types of fire extinguishers

The five types of fire extinguishers are water, foam, dry powder, CO2, and wet chemicals. And, although you don’t need to know all of them to use PASS fire safety in your home, understanding how they work will only boost your fire safety knowledge.

So, let’s briefly go over what class of fire each type of extinguisher can put out and how they work to combat fiery blazes.


Water extinguishers are often used in places where combustible materials like paper, wood, fabrics, and textiles are present. Thus, they’re the most common type of home fire extinguisher for Class A blazes. 

These extinguishers fight fires by cooling the fuel with water. As a result, they cause the flames to burn slowly until they’re all extinguished.


A foam fire extinguisher is the most effective for fighting a Class B flame. But, since they’re water-based, they also work for Class A fires. 

These extinguishers combat fires with their foaming agent, which produces a barrier between the flame and the fuel. The foam shoots out of the extinguisher and expands, growing larger and larger until it blankets the fire in a thick, white layer. In other words, it puts a heavy blanket over a fire to smother it and keep it from growing out of control.

Dry Powder

Of all the fire extinguisher classes, dry powder extinguishers are the most versatile as they’re typically labeled ‘ABC.’ Meaning they’re effective for combatting flames in those three fire classes. 

So, how do they work at tackling blazes? Well, the powder in the extinguisher works by smothering the fire and creating a barrier between the fuel and the oxygen that the fire feeds on to continue burning.


A CO2 extinguisher is effective at fighting flames started by flammable liquids and electrical equipment. So, they’re designed for Class B and c fire. 

CO2 fire extinguishers work by displacing the oxygen that fuels the fire, suffocating the flames and preventing them from spreading. The CO2 gas is also very cold, which helps to cool down the fire and prevent re-ignition.

Wet Chemical

Wet chemical extinguishers tackle Class K fires. Thus, they’re often used in commercial kitchens, restaurants, and other food preparation areas where cooking oils and fats are commonly used.

Because of the volatile nature of Class K flames, these types of extinguishers typically have a long, flexible lance that lets you apply the solution from a safe distance. This minimizes the risk of injury.

PASS fire safety

Now that you know the types of fire classes and the correlating extinguishers to fight them, you’re ready to learn how to use a fire extinguisher. 

So, let’s answer the question you’ve been waiting for: What does PASS stand for in fire safety?

The ‘P’ in PASS fire safety

The ‘P’ stands for ‘Pull.’ You have to pull the pin that’s at the top of the extinguisher. This will break the seal and allow you to use the extinguisher to fight the flames.

The ‘A’ in PASS fire safety

The ‘A’ stands for ‘Aim,’ as you need to aim the extinguisher properly. Now, while aiming the extinguisher at the fire rather than the corner that’s void of flames might seem obvious to you; the ‘A’ in PASS is more specific. 

You must aim the nozzle on the extinguishing agent at the base of the flames. This is because the base is where the fuel is. Therefore, it’s the part that needs to be put out to stop the fire from spreading.

The ’S’ in PASS fire safety

The first ’S’ in PASS stands for ‘Squeeze.’ You need to squeeze the handle to discharge the material, a.k.a the extinguishing agent that’s inside.

The ’S’ in PASS fire safety

The second ‘S’ stands for ‘Sweep.’ To exercise the proper use of a fire extinguisher, sweep the hose/nozzle from side to side across the base of the flames.

Home fire extinguisher safety: Common mistakes

Alright, so you know what PASS fire safety is now, but that doesn’t mean you’re immune to making mistakes should you find yourself amidst a blaze. So, let’s go over two common mistakes.

1. Ignoring instructions

Just as your fifth-grade teacher taught you to read instructions carefully on a test, reading the instructions on a fire extinguisher is critical. But, unlike a fifth-grade geography quiz, ignoring a fire extinguisher’s instructions can be life-threatening. So, review the instructions regularly as you may not have time to read them thoroughly in the event of a fire.

2. Neglecting maintenance

Neglecting fire extinguisher maintenance can leave you dry on a fire safety supply. OSHA requires a portable fire extinguisher to be tested and/or recharged every six years.

Don’t pass on the PASS in fire safety

Ensuring your safety in the event of a blazing disaster takes more than just attending one fire season safety presentation or browsing safety tips on Instagram during fire safety month. You have to regularly practice an evacuation plan and understand how to mitigate the risk of a fire igniting in your home.

But now that you’re aware of what the acronym PASS stands for, you’re one step closer to fighting off unprecedented flames. Tell your friends and family about PASS and you may just save a life.