Learn the Different Types of Fire Extinguishers

Fire extinguishers are essential tools for containing small fires before they escalate into dangerous and costly emergencies. However, choosing the wrong type of extinguisher can worsen a situation rather than resolve it. To stay compliant with UK fire safety regulations and to be prepared for real-life emergencies, it’s critical to understand the different types of fire extinguishers, which fire classes they’re suitable for, and how to properly use and maintain them.

In this guide, we’ll walk you through everything you need to know to choose the right fire extinguisher for your environment.

 

Understanding Fire Classes

The first step in selecting the correct fire extinguisher is knowing what kind of fire you may face. Fires are categorised into classes based on the type of fuel involved. In the UK, there are six main fire classes:

• Class A: Fires involving solid combustibles like paper, wood, cloth, and some plastics.
• Class B: Fires caused by flammable liquids such as petrol, paint, and solvents.
• Class C: Fires involving flammable gases like propane and butane.
• Class D: Fires involving combustible metals such as magnesium, lithium, and titanium.
• Class F (sometimes referred to as Class K in US standards): Fires caused by cooking oils and fats.
• Electrical Fires: While not officially a separate class in the UK, electrical fires are a key concern and require non-conductive extinguishing agents.

Each class requires a specific type of extinguisher, which we’ll cover below.

 

Types of Fire Extinguishers 

Each extinguisher is designed for specific fire classes. Understanding the differences can save lives and prevent property damage. 

Water Fire Extinguishers

Ideal for Class A fires, water extinguishers cool the fire below ignition point. They’re easily recognisable by their red label but should never be used on flammable liquids or electrical fires. 

• Use for: Class A fires
• Not for: Flammable liquids, electrical, or kitchen fires
• Label Colour: Red
• How it works: Cools the burning material below its ignition temperature
• Common locations: Offices, schools, residential buildings

Foam Fire Extinguishers

Foam extinguishers are suitable for Class A and B fires. They work by blanketing the fire, cutting off the oxygen supply. These are often used in garages, workshops, and environments where flammable liquids are present. 

• Use for: Class A and B fires
• Not for: Electrical or gas fires
• Label Colour: Cream
• How it works: Creates a blanket to smother liquid fires and cools solid fires
• Common locations: Garages, workshops, warehouses

Dry Powder Fire Extinguishers 

Highly versatile, dry powder extinguishers handle Class A, B, and C fires. They work by disrupting the chemical reaction of the fire and displacing oxygen. While effective, they can be messy and are best used in well-ventilated spaces. 

• Use for: Class A, B, and C fires; some can handle electrical fires
• Not ideal for: Enclosed spaces due to inhalation risk
• Label Colour: Blue
• How it works: Interrupts the chemical reaction and removes oxygen
• Common locations: Industrial settings, fuel stations, garages

Carbon Dioxide (CO₂) Fire Extinguishers

Common in offices and server rooms, CO₂ extinguishers are ideal for electrical and flammable liquid fires (Class B and C). They leave no residue but should not be used in enclosed spaces due to the risk of asphyxiation. 

• Use for: Electrical and Class B fires
• Not for: Class A or kitchen fires
• Label Colour: Black
• How it works: Displaces oxygen and cools the fire
• Common locations: Server rooms, offices, electrical cupboards

Wet Chemical Fire Extinguishers 

These are specialised for Class K fires in commercial kitchens. Wet chemical agents react with the hot oil, cooling and smothering the fire while preventing reignition. 

• Use for: Class F (cooking oil fires)
• Not for: Electrical or flammable liquid fires
• Label Colour: Yellow
• How it works: Reacts with hot oil to form a soapy layer that cools and smothers
• Common locations: Commercial kitchens, food trucks, restaurants

Specialist Fire Extinguishers 

Certain environments require unique solutions. Class D fires, for example, need specific dry powder agents. Clean agent extinguishers like FM-200 are used in data centres and museums, where residue must be avoided. 

Newer Extinguisher Types: Water Mist and All Fires

In addition to traditional extinguishers, new-generation types such as Water Mist and All Fires extinguishers are being introduced. Designed to be safer and more versatile, these can tackle multiple fire classes, including electrical fires in many cases, and are set to eventually replace many of the older, single-purpose extinguishers currently in use.

Choosing the Right Fire Extinguisher

The key to effective fire safety is selecting the correct extinguisher based on your specific risk environment.

Assessing Fire Risks

Begin by identifying potential fire hazards in your space. A kitchen might need Class K protection, while a factory may require dry powder and foam extinguishers. If you’re responsible for workplace fire safety, enrolling in Fire Marshal Training is a smart way to build competence and meet legal requirements.

Placement of Fire Extinguishers

Fire extinguishers should be mounted visibly near fire risks and exits—never hidden or blocked. Proper signage is essential to ensure they can be accessed quickly during emergencies.

Regular Maintenance and Training

Routine inspections, servicing, and recharging ensure extinguishers remain functional. Equally important is training. All staff should know how to use extinguishers correctly. Attending a fire safety course or running regular fire drills helps build confidence and preparedness across your team.

Understanding the types of fire extinguishers, including newer options like Water Mist and All Fires extinguishers, and their applications is a crucial part of any fire safety strategy. By learning about fire classes, choosing the right extinguishers, and placing them correctly, you can significantly reduce the risk of a fire emergency turning into a disaster.

For those looking to go beyond the basics, Franklin’s Training offers comprehensive fire safety courses tailored to real-world environments, helping you stay compliant, confident, and prepared.