Types of Fire Extinguishers Explained - Fire Classes A–F Guide

Understanding the different types of fire extinguishers and the fire classes they are designed for is essential for keeping people and workplaces safe. Using the wrong extinguisher can be ineffective, or even dangerous, so it’s important to know which type to use in an emergency.

This guide explains fire extinguisher types, fire classes, and how to choose the right one.

At Virtual College, we understand the importance of fire safety knowledge in the workplace. Our health and safety training courses can help you and your team to be as prepared as possible for any potential fire emergencies.

What are fire extinguisher classes?

Fire extinguisher classes categorise fires based on the type of material that is burning. Each class requires a specific extinguishing method.

In the UK, fires are divided into the following classes:

• Class A – Fires involving solid materials such as wood, paper, and textiles
• Class B – Fires involving flammable liquids like petrol, diesel, or paint
• Class C – Fires involving flammable gases such as propane or butane
• Class D – Fires involving combustible metals like magnesium or aluminium
• Class F – Fires involving cooking oils and fats, typically in kitchens

Choosing the correct extinguisher for each class is critical to safely controlling a fire.

Fire extinguisher types and their uses

Below shows which fire extinguisher should be used for each type of fire:

• Class A
  Fires involving wood, paper, and textiles
  Recommended extinguishers: Water, Foam, Powder
• Class B
  Fires involving flammable liquids
  Recommended extinguishers: Foam, CO₂, Powder
• Class C
  Fires involving flammable gases
  Recommended extinguishers: Powder
• Class D
  Fires involving combustible metals
  Recommended extinguishers: Specialist Dry Powder
• Class F
  Fires involving cooking oils and fats
  Recommended extinguishers: Wet Chemical

There is no single fire extinguisher suitable for all fire types, so understanding these differences is essential.

What are the 5 types of fire extinguishers?

The five main types of fire extinguishers are:

• Water extinguishers
• Foam extinguishers
• CO₂ extinguishers
• Dry powder extinguishers
• Wet chemical extinguishers

Each type is designed to tackle specific fire risks.

Water fire extinguishers

Water extinguishers are the most common type and are used for Class A fires involving solid materials like wood, paper, and textiles.

Best for:

• Offices
• Schools
• Warehouses

Do not use on:

• Electrical fires
• Flammable liquids

Foam fire extinguishers

Foam extinguishers are effective on Class A and Class B fires. They work by forming a barrier over the burning material, preventing oxygen from feeding the fire.

Best for:

• Petrol stations
• Garages
• Workshops

Do not use on:

• Electrical equipment (unless specified)

CO₂ fire extinguishers

CO₂ extinguishers are ideal for electrical fires and Class B fires. They work by displacing oxygen and cooling the fire.

Best for:

• Offices with electrical equipment
• Server rooms

Do not use on:

• Class A fires (limited effectiveness)

Dry powder fire extinguishers

Dry powder extinguishers are versatile and can be used on Class A, B, and C fires. They interrupt the chemical reaction of a fire.

Best for:

• Industrial sites
• Outdoor areas

Limitations:

• Can reduce visibility
• Not ideal for enclosed spaces

Wet chemical fire extinguishers

Wet chemical extinguishers are specifically designed for Class F fires, involving cooking oils and fats.

Best for:

• Commercial kitchens
• Restaurants

They work by cooling the fire and creating a barrier to prevent re-ignition.

How to choose the right fire extinguisher

Choosing the correct fire extinguisher depends on the environment and fire risks present.

• Offices: Water and CO₂ extinguishers
• Kitchens: Wet chemical extinguishers
• Industrial settings: Dry powder extinguishers
• Mixed environments: Combination of extinguisher types

A proper fire risk assessment will help determine what is required.

Can one fire extinguisher be used for all fires?

No, there is no single fire extinguisher that is safe and effective for all fire types. Using the wrong extinguisher can make a fire worse or create additional hazards.

Risk Assessment

It's crucial to conduct a thorough fire risk assessment to determine the proper number and types of fire extinguishers for your business. This assessment should be carried out by a competent person (such as a fire safety professional) and reviewed regularly as part of your overall fire safety management plan.

Fire safety training and next steps

Understanding fire extinguisher types is just one part of workplace safety. Proper training ensures that staff know how to respond effectively in an emergency.

Browse our fire safety training course today and give your team the confidence to respond when it matters most.