Dry powder fire extinguishers are some of the most popular extinguishers on the market thanks to just how versatile they are. They are used for a wide range of fire safety situations. They have even earned the name ABC extinguishers due to their ability to fight Class A, B, and C fires.  

However, no matter how versatile or useful an extinguisher might be, that’s only true if you understand how to use it safely. An improperly used dry powder fire extinguisher is not only not going to be as effective as it could, but it could potentially be very dangerous. 

In this blog, we’re going to look at how to use a dry powder fire extinguisher. We’re going to discuss how dry powder extinguishers work and where they are most useful. After that, we will discuss the potential dangers that misuse of dry powder fire extinguishers can cause. Finally, we will go through the process of safely using a dry powder extinguisher in the event of a fire.  

How do dry powder fire extinguishers work? 

The agent inside a dry powder fire extinguisher is usually made up of mono-ammonium phosphate. There are other powders used in fire extinguishers such as sodium bicarbonate and B plus powder. These each have different uses for different classes of fire, but you will find that they are often clearly labelled. If an extinguisher is simply called a Dry Powder Fire Extinguisher, it’s likely that it contains mono-ammonium phosphate. 

When the extinguisher is used, the powder is pushed out by a compressed gas. The powder falls over the fire and creates a blanket that covers it. This removes one of the central things that a fire requires to burn: oxygen. A fire needs oxygen, a fuel, and an ignition source. If you take away even one of these things, the fire won’t be able to spread.   

Where would you need a dry powder extinguisher? 

When choosing a fire extinguisher, you need to be sure that you carefully consider what your needs are. No fire extinguisher can cover all possible classes of fire, which means you need to know the kinds of fire that you’re at risk for to decide on the right fire extinguisher.  

To find out what kind of fire extinguishers you need, it’s essential that you conduct a Fire Risk Assessment. A Fire Risk Assessment is the process through which you assess the fire hazards in your building, recognise who might be particularly at risk, reducing risks documenting findings, and consistently reviewing your findings. 

Without a Fire Risk Assessment, you’re not going to be able to accurately recognise the right fire extinguisher for your needs. 

When it comes to dry powder fire extinguishers, they are most useful in environments where you might be at risk for Class A (combustible solids), B (flammable liquids), C (flammable gases), and some electrical fires (below 1000v). 

Potential hazards 

While dry powder fire extinguishers are very useful for a range of situations, they aren’t without potential issues that you should be aware of. 

Chance of re-ignition 

Dry powders typically do not provide a cooling effect on a fire, which means that they do come with a small risk of re-ignition. This risk can be reduced by ensuring that you always use a dry powder extinguisher on the right types of fire, and you never try to fight a fire that is too large. 

Debris 

Dry powders can sometimes pose potential issues when it comes to mess. When dry powder fire extinguishers are discharged, they can create a large amount of mess when used which requires time and effort to clean up. It can even leave residue that may require multiple cleans to remove. 

Use in enclosed spaces 

When used in enclosed spaces, dry powders can obscure vision which can make escape from a fire more difficult. There is also an increased chance of inhaling the powder when they are used indoors. When inhaled, the powder inside dry powder fire extinguishers can cause shortness of breath and coughing. 

Use on sensitive equipment 

When it comes into contact with moisture, ABC powder can become corrosive. That means that, while dry powder fire extinguishers can be used on some electrical fires, there are risks involved in using them on sensitive electronic equipment like computers. The powder can corrode and damage the equipment, leading them to need to be replaced. Though, it is important to remember that equipment can be replaced. Human life can’t.  

Using a dry powder fire extinguisher safely  

When it comes to fighting any kind of fire, remember that you should only attempt to tackle small, controlled fires. If you are in doubt about your ability to fight a fire, you should leave the building immediately and wait for the fire brigade. 

However, if you do feel equipped to tackle a fire, there are some important steps that you need to take to use a dry powder fire extinguisher safely. 

Check the extinguisher is safe to use  

Before you use a dry powder fire extinguisher, you should check the pressure gauge is in the green. This ensures that the extinguisher is safe to use. Then, remove the safety pin to break the anti-tamper seal. The extinguisher is now ready to use. 

Assess the fire  

There are several factors that you need to consider when it comes to the fire you are attempting to tackle. The first is the fire classification. A dry powder fire extinguisher is usually able to tackle Class A, B, C, and Electrical fires (below 1000v). If you are dealing with another type of fire, such as one resulting from cooking fats or high voltage electricity, a different fire extinguisher should be used. 

You should also assess the size of the fire. If the fire is small and controlled, you may be able to fight it yourself. However, if the fire is large and appears to be spreading quickly, you are much safer simply exiting the building and calling the fire brigade. Your safety should always come before attempting to fight any fire. 

Know your exits 

Before you begin operating the dry powder extinguisher, make sure that you have a clear path of evacuation. You need to be able to make a safe exit. Your fire extinguisher bracket should be installed in a location with multiple exit options nearby. When fighting the fire, make sure that you always keep your back to an exit. 

Using the extinguisher  

You’re now ready to begin using your dry powder fire extinguisher. In order to remember the process, use the acronym: PASS. 

• P – Pull the pin from the handle. This will break the seal so that you can use the extinguisher. 

• A – Aim the hose of the extinguisher at the base of the fire. This is because want to extinguish the fire at its source. 

• S – Squeeze the lever slowly, applying consistent pressure. 

• S – Sweep the hose from side to side, providing even cover from the powder, aimed at the source of the fire. As the fire dies down, you can begin to move closer.  

If the fire is too strong 

If, after using the PASS method, you find that the fire has still not died down, do not continue to fight it. Exit the building right away and retreat to a safe place from which to call the fire brigade.  

Conclusion 

Dry powder fire extinguishers are a valuable addition to many environments. As with all aspects of fire safety, understanding how to properly use a dry powder fire extinguisher is an essential part of keeping yourself and others safe.  

If you think that your building needs dry powder fire extinguishers, your existing dry powder fire extinguisher needs replacing, or you want additional guidance on using dry powder fire extinguishers safely, get in touch with one of our qualified engineers on 0330 058 0631, or contact us online here.