The Basics of Fire Extinguishers at Work

fire extinguishers in a row

Learn how to use extinguishers properly to remove fire hazards in the workplace

Fire extinguishers are one of the most important and effective pieces of fire safety equipment in any workplace. From basic shop fronts to large industrial factories, having the right fire extinguisher at hand if something should go wrong can — and does — save lives every year.

That said, fire extinguishers can also cause injury if used incorrectly, or used on the wrong type of fire. Therefore, fire safety and fire extinguisher training should always be taught to any employee in charge of using one.

Which fire extinguisher should I choose?

Fire starts when a combustible material (such as wood or paper) mixes with oxygen and heat.
Fire extinguishers are designed to starve a fire of one of the vital parts of the “fire triangle”, thus putting it out. By removing the fuel, oxygen, or the heat source, the fire cannot keep burning or spread.

Since there are multiple types (or classes) of fire, there also needs to be different types of fire extinguisher to effectively combat them. The type you need to use in your workplace is based upon the risk of a certain fire igniting during your day-to-day business processes.

For example, it’s unlikely a chemical fire would start in an office, so a chemical fire extinguisher wouldn’t be suitable or particularly useful. Instead, the risk of an electrical fire would be higher, due to a high number of wires and plugs, so a fire extinguisher for electrical fires is more useful in this regard.

The fire risk assessment (which is a legal requirement for all premises), will ultimately determine the type and quantity of fire extinguishers required.

How do I use a fire extinguisher?

Using a fire extinguisher is relatively straightforward, but fire marshal training should always be given to employees nominated as fire marshals. Identifying the type of extinguisher to use on the variety of different fire types is extremely important, as choosing the incorrect extinguisher can make matters worst.

Although the below covers the basics of use, you must ensure that proper training is provided in their use.

The PASS system

The PASS system is an easy way to remember how to set up and use a fire extinguisher. Please note: this does not count as training for the correct use of a fire extinguisher. We’d suggest getting training before use.

Pull the safety pin and tag, unlocking the lever on top
Aim the nozzle (or hose) at the base of the fire (or as directed if using a specialised extinguisher)
Squeeze the handle, activating the extinguisher
Sweep the nozzle or hose across the fire until it has been extinguished completely

The different types of fire extinguishers

Water Extinguishers


The most basic type of extinguisher, water extinguishers use a jet of water to cool down and prevent combustible materials from continuing to burn. They should only be used on Class A fires and should never be used on electrical or chemical-based fires.
Foam Extinguishers


Foam extinguishers can be used on Class A and Class B fires and are designed to completely engulf a fire’s fuel source in foam, starving it of oxygen and slowing down the reaction process. Foam extinguishers should not be used on electrical fires, as they can cause injury to the user through shock.
CO2 Extinguishers


CO2 extinguishers fire a large blast of CO2 gas at a fire to starve it of the oxygen needed to keep combustion going. CO2 extinguishers are effective for electrical fires and Class B liquid fires, and should be found in buildings that have electrical fire risks.
Powder Extinguishers


Powder extinguishers are ideal for use on Class A, B, C and flammable gas fires, making them good all-rounders for almost any type of fire. They emit a jet of powder that removes the amount of oxygen getting to the fuel source, preventing the fire from burning as intensely.
Wet Chemical Extinguishers


Wet chemical extinguishers are used on fires such as oil or fat fires that happen in restaurants and kitchens. Oil and fat fires can end up exploding if water is added and many other extinguishers are ineffective at removing the danger. Wet chemical extinguishers are purpose-built for these types of fires and should always be at hand if you work in a kitchen or restaurant.

 Fire extinguisher use: what are the classes of fire?

Fires can be started by a variety of different sources, from electrical malfunctions to burning coal fires or chemicals. As such, different types of fire are classed by a certain letter:

Class A Fires


Class A fires are ordinary materials such as wood, plastic, or materials that have been ignited. They’re the most common type and are relatively easy to control with the right training and fire extinguishing equipment.
Class B Fires


Class B fires are flammable liquids which are easily ignitable, such as petrol, kerosene, paints, or solvents. These require a specific type of extinguisher to put out correctly and can be dangerous without proper training and quick action.
Class C Fires


Class C fires are caused by flammable gases such as propane, methane and petrol-based gases. The types of fires are almost impossible to put out with anything other than a powder fire extinguisher. Without proper training, Class C fires can be extremely dangerous, if not lethal.
Class D Fires


Although rare, Class D fires can be difficult to put out. Caused by certain types of metals such as potassium or magnesium, these fires require specialist training and extinguishing equipment. Your workplace will most likely have training specific to your requirements if these materials are used.
Class E Fires


Class E fires are caused by electrical short circuits or malfunctions and are dangerous to put out with certain types of foam and water-based fire extinguisher. CO2 extinguishers should be available if there is any potential risk from these types of fires.

Fire safety training

All employees should be aware of the risks of uncontrolled fires in the workplace, regardless of the industry. Fire safety awareness training for employees covering areas such as fire escape plans, the chemistry and causes of fires, and what to do in case of a fire is a good place to start in terms of demonstrating appropriate awareness training for employees.

Howlett Health and Safety Services fire safety training provides sufficient information to demonstrate compliance with current health and safety requirements. Check out either our basic fire safety awareness training, our  fire marshal training or our fire extinguisher training pages for futher information.

Not sure if your workplace has the right fire extinguishers? Worried about your current fire safety standards? Howlett Health & Safety’s services are here to help. Get in touch today!

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