A guide to the different types of Fire Extinguishers

Whatever industry you’re in, understanding the different types of fire extinguisher is essential to protecting lives and complying with legislation. Your business’ environment will be at risk of certain classes of fire, which must dictate the fire extinguisher types you keep on premises. In addition to this, adequate safety signage is required to ensure occupants know which fire extinguisher to use. Here, we offer a comprehensive guide to fire extinguishers, including important information about regulations, the various classes of fire your business may be at risk of, and everything you need to know about each type of fire extinguisher.

Fire Extinguisher Regulations

There are several pieces of legislation relating to fire extinguishers on your premises. However, the two that are frequently referred to are the British Standards (BS 5306) and the Regulatory Reform (Fire Safety) Order (RRFSO). These include essential practises for your business. 

For example, all businesses are required to keep at least two water fire extinguishers onsite, as these are the safest to use, and can tackle the most common type of fire. In addition, extinguishers should be inspected for signs of tampering or discharge every month, while being annually serviced to ensure they are in working order. The BS 5306 also highlights the importance of fire safety signs and their placement throughout your business. Not only must they be highly visible, but they must direct and inform employees, guests and/or residents of the appropriate actions to take in the event of a fire.

The RRFSO is particularly important as it outlines the need for businesses to appoint a ‘responsible person’ to oversee and take responsibility for fire safety. This should be the business owner or site manager. One of the most important functions of the responsible person is to carry out a risk assessment, highlighting potential fire risks before implementing (and recording) steps to minimise or remove their likelihood or impact. 

For example, upon conducting a fire risk assessment, a construction site’s responsible person might identify the proximity of storage materials and essential pieces of electrical equipment as a fire risk. As a result, they would install an electrical fire extinguisher with appropriate signage, and ensure the electrical equipment has been inspected for damage and recently serviced.

To learn more about the different types of fire safety signage, read our guide to fire safety signs now.

What are the different classes of fire?

The class of a fire relates to a fire’s fuel source, and it is absolutely crucial that you understand the differences to avoid making a fire worse. Using the wrong type of extinguisher for the class of fire could quickly put more lives at risk and damage the property beyond repair. Here, we go through each class of fire in detail.

Class A fire
A Class A fire involves carbonaceous materials such as wood, paper and textiles. These are one of most common types of fire as all businesses either store or are furnished with such materials.

Class B fire
A less common but equally dangerous class of fire, Class B fires involve flammable liquids like spirits and petrol and are more common in garages, restaurants and factories.

Class C fire
A Class C fire is a fire involving flammable gases. These are extremely dangerous as they can cause explosions and pose a great risk to environments such as factories.

Class D fire
While many premises are not at risk of this class of fire, Class D fires - those involving burning metals - pose a very real risk to manufacturing businesses as only very specific and limited types of extinguisher can be used.

Electrical fire
Electrical fires are caused by faulty equipment, exposed wires or the introduction of water or another conductive to a live current. Given the wide-spread use of electricity, all businesses are at risk of this class of fire.

Class F Fire
Lastly, a Class F fire involves cooking oils and fats. These are particularly dangerous if tackled using the wrong extinguisher as any water-based solution will mix and spread the flames across a larger surface. Naturally, commercial kitchens and restaurants are at greater risk of Class F fires. 

While you now understand the different classes of fire, the crucial question remains: which fire extinguisher should I use for each class of fire?

Types of fire extinguishers

There are unique fire extinguisher colours on each label for quick identification, demonstrating which classes of fire they can be used on.

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Fire extinguisher signs

In the event of an emergency, fire extinguishers must be easily identified to ensure their correct use. This is why fire extinguisher signs are so important; they provide clear instruction and help save lives. Fire extinguisher ID signs are required by law and display the type of fire extinguisher and which classes of fire they are suitable for. However, fire safety signage does not just relate to fire extinguishers and must be installed throughout the premises (fire door, evacuation routes and assembly point signs).

Where to locate fire extinguishers

To comply with the British Standards, a suitable fire extinguisher should never be more than 30 metres from anyone on a premises. Suitable fire extinguishers - i.e. fire extinguishers which pertain to the specific fire risks of your premises - should be identified during a fire risk assessment and installed in an easily accessible place, whilst being protected from accidental damage, tampering and adverse weather conditions. This is another stipulation of the British Standards. Use wall-mounted stands and fire storage cabinets to keep fire extinguishers available and protected, whilst installing anti-tampering tags to demonstrate whether it has been used or not. Fire extinguishers should not obstruct fire escape routes or be kept directly in the vicinity of a fire risk. For example, if a Class C fire extinguisher was kept next to a flammable gas container, and a fire broke out, it would be inaccessible due to its proximity to the fire, rendering it ineffective. 

Fire extinguisher FAQs 

Do fire extinguishers expire? 
Technically, many fire extinguishers do not come with an expiration date and can last between 10 to 20 years if properly maintained. However, many factors, such as rust, adverse temperatures and improper use, can cause a fire extinguisher to become less effective. 

How to use a fire extinguisher?
The correct method of using a fire extinguisher is the PASS method: 

Pull the pin from the extinguisher
Aim the nozzle at the base of the fire
Squeeze the handle
Sweep from side to side to adequately extinguish the fire
Can fire extinguishers be refilled? 
Yes, fire extinguishers can be refilled and should be put through a discharge test every five years. This is where they are fully emptied to ensure they are in working order before being refilled by a qualified technician. 

How many fire extinguishers do I need?
The BS 5306 stipulates that workplaces should have at least two fire extinguishers on every floor, unless the area is very small (under 100m2). However, the British Standards also require that people should never be more than 30 metres away from a fire extinguisher, so placement and volume of fire extinguishers is truly dependent on your premises. 

Are fire extinguishers flammable? 
While fire extinguishers are not flammable, they are highly pressurised containers and can explode if exposed to intense heat. This is why fire extinguishers should be placed a safe distance from a fire risk. 



While fire extinguishers are vital to protecting lives, ensuring your fire safety signage is up to date and adequate is just as important as it informs and directs people through an emergency. Browse our extensive range of fire safety signs and, if you can’t find what you’re looking for, our custom sign service may be perfect for you. Contact us by phone, email or web chat to discuss your business’ fire safety signage needs.