5 Types of Fire Extinguishers
There are different types of fire extinguishers for fighting various classes of fire. It is critical to understand the applications and risks of using each type of extinguisher.
There are 5 main types of fire extinguishers:
As part of any workplace fire strategy, the responsible person needs to decide on suitable fire-fighting equipment to install within their premises.
Being able to immediately distinguish them apart could make a lifesaving difference. Your Fire Risk Assessment should help you decide between the different types of fire extinguishers for each area or zone.
Each Fire Extinguisher type is easily identifiable by their names, colours, and sometimes their hoses; it’s easier than you think to identify them from one another.
Each type of fire extinguisher is ergonomically designed for the safe and effective discharge of its contents. They each contain different materials that make them suitable for fighting certain types of fires.
The correct one must be used for the relevant fire class, otherwise they may prove ineffective, aggravate the fire or create a hazard for the responder.
Let’s take a look at each type of fire extinguisher, their uses, and their risks.
These types of fire extinguishers will be solid red and will have the word ‘water’ printed across them in white text.
They are your classic model: they dispense water at a high pressure to extinguish flames.
Water extinguishers are only suitable for class A fires, which means they can fight fires that involve wood, cloth, paper, plastics, coal, and other similar materials.
Warning: do not use on burning fat and oil fires and electrical appliances!
Dry Mist Water Extinguishers
These types of fire extinguishers will be solid red and will have the words ‘water mist’ printed within a white rectangle.
Dry water mist extinguishers are unique in that they can combat almost all types of fires, including class F fires that are usually difficult to attack.
The extinguisher’s supersonic nozzle converts water into ‘dry’ microscopic particles, which are then drawn into the fire and simultaneously cool and suffocate it – successfully extinguishing the flames.
They are also effective for fire-fighting because they form a safety barrier between the user and the fire – which repels some of the heat – and leave no hard-to-clean residue behind.
CAUTION: Although they are not currently classified as suitable for fighting class B (liquids) and C (gases) fires, dry water mist extinguishers have been identified as effective against them. They are not suitable for electrical fires.
These types of extinguishers will say ‘powder’ in white text over a blue rectangle, and underneath the rectangle will be written ‘ABC powder’.
As their name suggests, these are designed to combat class A, B, and C fires – those involving solids, liquids, and gases.
The powder acts as a thermal blast that cools the flames so burning cannot continue. Due to their non-conductive nature, they are also suitable for fighting electrical fires. However, they do not effectively penetrate the spaces in equipment easily, so the fire could still re-ignite.
Disadvantages of Powder Extinguishers
CAUTION: Do not use foam extinguishers on domestic chip or fat pan fires (class F).
The downside to ABC powder extinguishers is that they pose a danger of inhalation when used in close spaces.
They also leave residue behind that is difficult to clean up and causes damage to soft furnishings, carpets, and computers.
These types of extinguishers are identifiable by the word ‘foam’ printed within a cream rectangle on their bodies.
Foam extinguishers are primarily water based and contain a foaming agent, which has rapid flame knock-down and a blanketing effect – it smothers the flames and seals vapours so that re-ignition cannot occur.
They are suitable for fighting class A and B fires.
When used against class A fires, the user can simply point and spray. However, when used against class B fires – those with flammable liquids – they should not be sprayed directly into the liquid. This could cause the fire to be pushed and spread to surrounding areas. The best method of application is to spray the foam nearby so that it can build up and flow across it.
Warning: these should not be used on any other fire classes, especially chip or fat pan fires. They should not be used to fight electric fires.
Carbon Dioxide (CO2)
These types of extinguishers can be identified by the text ‘CO2’ printed in white on a black rectangle. They also have a distinct type of hose unlike other extinguishers.
Carbon dioxide extinguishers are used for combating class B and electrical fires – they suffocate the fire by displacing oxygen in the air.
Because they do not leave any substances behind, unlike other extinguishers, they are particularly useful for offices and workshops where electrical fires may occur as they minimise damage done to equipment.
CAUTION | They must not be used on deep fat fryers (class F fires). The strong jet from the extinguisher would propel the burning fat out of the fryer and spread the fire to surrounding areas.
Whilst carbon dioxide is effective at smothering fires, once the gas has floated away, the fire may re-ignite if the source has not been removed.
These types of fire extinguishers are identifiable by the words ‘wet chemical’ printed across a canary yellow rectangle. It also has an extended applicator.
Wet chemical extinguishers are designed for combating fires that involve class F fires.
They are effective because they are capable of dissipating fires that are of an extremely high temperature – namely, cooking oils and fats.
The best method of application is to spray in slow circular motions. The user should empty the entire contents onto the oil/fat. Otherwise, the fire may re-ignite.
Warning: wet chemical extinguishers are usually not recommended for class B fires – those involving liquids. Also, although they are capable of combating class A fires, they are not as effective as other extinguishers at doing so.
What are the Different Classes of Fires?
Fires come in many forms, so you need to familiarise yourself with how to properly and swiftly extinguish whichever type of fire you face.
Fires must be fought carefully depending on the materials involved. That is why they have been classified in 6 different categories:
- Class A – Fires that involve solid or organic materials, such as wood, plastics, paper, textiles, or coal.
- Class B – Fires that involve flammable liquids, such as gasoline, petroleum oil, paint, or diesel.
- Class C – Fires that involve flammable gases, such as propane, butane, or methane.
- Class D – Fires that involve combustible metals, such as magnesium, lithium, sodium, potassium, titanium, or aluminium.
- Class F – Fires that involve cooking oils and fats, such as vegetable oil, sunflower oil, olive oil, maize oil, lard, or butter (typically those used for deep-fat fryers).
- Although it is not recognised as a separate class of fire in Europe, electrical fires that involve live equipment and electrical sources are also a type you should bear in mind (think of it as an informal Class E; ‘E’ for electric to help you remember).
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