Fire extinguishers are an essential part of any workplace fire safety plan. They are your first line of defence against small fires that, if unchecked, can escalate into life-threatening situations. Understanding the various types of fire extinguishers and their proper usage is crucial for ensuring safety in the workplace.
At Folgate Safety, we not only specialise in fire extinguisher installation and maintenance, but we also offer a range of fire safety services, including fire alarms, fire doors, and comprehensive fire safety training.
This guide will explain the different types of fire extinguishers, the importance of understanding fire signs, and how to ensure your business complies with UK fire safety regulations.
Disclaimer:
The information provided in this blog post is for general informational purposes only and is not intended to serve as professional advice or guidance for specific fire safety situations. While we aim to offer accurate and up-to-date content, each property and business has unique fire risks that must be addressed by trained professionals.
Proper fire risk assessments should always be conducted by certified fire safety experts to ensure compliance with local regulations and the highest level of safety. We recommend consulting with trained professionals, such as those at Folgate Safety, for tailored advice, inspections, and the installation of appropriate fire prevention systems.
The Science Behind Fires: The Fire Triangle and Fire Tetrahedron
Before exploring the various fire extinguisher types, it’s important to understand the science of how fires start and sustain. Fires need three essential components to ignite, known as the Fire Triangle:
Heat – An ignition source, such as a flame or spark, that raises the temperature of a material to its combustion point.
Fuel – Any combustible material that can burn, including paper, wood, or flammable liquids.
Oxygen – The air or oxygen that sustains combustion.
Removing any one of these elements will extinguish the fire. However, modern fire safety science also includes a fourth element in the Fire Tetrahedron—the chemical reaction that sustains the fire. By breaking this chemical chain reaction, fire extinguishers can extinguish a fire more effectively.
Understanding Fire Extinguisher Types
Fire extinguishers are classified based on the type of fire they are designed to fight. In the UK, different fire extinguisher types are identifiable by specific colours and symbols, ensuring quick and easy identification during an emergency. Here’s a breakdown of the most common fire extinguisher types, their uses, and how they work.
1. Water Fire Extinguishers
Water extinguishers are the most common and widely recognised type of fire extinguisher. They are designed to tackle Class A fires, which involve ordinary combustible materials like wood, paper, cloth, and textiles.
Label Colour: Red
Fire Classes: Class A
How It Works: Water extinguishers cool the heat component of the fire triangle, lowering the temperature below the ignition point and stopping the fire.
When to Use: Water extinguishers are ideal for everyday settings like offices, schools, and warehouses where there are large amounts of solid combustible materials.
When Not to Use: Water extinguishers should never be used on electrical fires or flammable liquid fires (Class B), as water can conduct electricity and spread the fire.
2. Foam Fire Extinguishers
Foam extinguishers are versatile and designed to handle both Class A and Class B fires (fires involving flammable liquids like petrol, oil, and paints).
Label Colour: Cream
Fire Classes: Class A and Class B
How It Works: Foam extinguishers work by forming a blanket of foam that smothers the fire, cutting off the oxygen supply and preventing re-ignition.
When to Use: Foam extinguishers are ideal for environments where flammable liquids are present, such as garages, workshops, or kitchens. They also work well on ordinary combustibles like wood and paper.
When Not to Use: Foam extinguishers should not be used on electrical fires as the foam is conductive and could cause harm.
3. CO2 (Carbon Dioxide) Fire Extinguishers
CO2 extinguishers are specifically designed for use on electrical fires and Class B fires.
Label Colour: Black
Fire Classes: Class B and electrical fires
How It Works: CO2 extinguishers displace the oxygen around the fire, suffocating it. Additionally, the CO2 is cold as it exits the extinguisher, helping to cool the fire and prevent re-ignition.
When to Use: CO2 extinguishers are ideal for office environments with electrical equipment such as computers, servers, and electrical appliances. They are also effective against flammable liquid fires.
When Not to Use: CO2 extinguishers are not suitable for Class A fires (solid combustibles like wood and paper) as they may not prevent re-ignition. The cooling effect is also less effective on larger solid fuel fires.
4. Dry Powder Fire Extinguishers
Dry powder extinguishers are often referred to as “multi-purpose” extinguishers because they can be used on a wide range of fire classes, including Class A, Class B, Class C (flammable gases like propane, butane, and methane), and Class D fires (flammable metals).
Label Colour: Blue
Fire Classes: Class A, B, C, and D
How It Works: The dry powder works by interrupting the chemical reaction in the fire tetrahedron, breaking the chain reaction that sustains the fire.
When to Use: Dry powder extinguishers are suitable for high-risk environments like industrial sites, garages, and workshops where a variety of combustible materials are present.
When Not to Use: These extinguishers are not recommended for enclosed spaces, as the powder can reduce visibility and cause respiratory issues. They are also less effective at cooling and preventing re-ignition.
5. Wet Chemical Fire Extinguishers
Wet chemical extinguishers are designed specifically for Class F fires, which involve cooking oils and fats, commonly found in commercial kitchens.
Label Colour: Yellow
Fire Classes: Class F
How It Works: The wet chemical extinguishes the fire by forming a thick layer of soapy foam on top of the burning oil, cutting off the oxygen and cooling the fire.
When to Use: Wet chemical extinguishers are essential for any kitchen, especially those using deep fat fryers.
When Not to Use: These extinguishers should not be used on electrical fires or Class B fires (flammable liquids).
6. Specialist Fire Extinguishers for Class D Fires
Class D fires involve combustible metals such as magnesium, titanium, and lithium. These types of fires are common in industrial and manufacturing environments where metal dust or metalworking occurs.
Label Colour: There is no specific colour; they are typically identified by the Class D marking.
Fire Classes: Class D
How It Works: Specialist extinguishers use dry powder to smother the fire, isolating it from oxygen and interrupting the chemical reaction.
When to Use: These extinguishers should only be used for metal fires and are highly specialised.
Fire Extinguisher Colours and Fire Signs: Ensuring Quick Identification
In an emergency, being able to quickly identify the right fire extinguisher is crucial. This is why fire extinguishers in the UK are colour-coded. Additionally, workplaces are required to display fire signs indicating the location of extinguishers and the type of fire they are suitable for.
At Folgate Safety, we provide comprehensive fire extinguisher installation services that include proper placement, signage, and guidance on using the right extinguisher for each fire type. Regular maintenance and inspections are also part of our offering, ensuring that your fire safety equipment is always in working order.
How Do Fire Extinguishers Work?
The basic mechanism of all fire extinguishers is to interrupt one or more of the components of the fire triangle or fire tetrahedron:
Cooling: Water extinguishers remove heat from the fire, reducing it below its ignition point.
Suffocating: Foam, CO2, and dry powder extinguishers work by cutting off the oxygen supply to the fire.
Disrupting the chemical reaction: Dry powder and specialist extinguishers break the chemical reaction, stopping the fire from sustaining itself.
Each type of extinguisher is specifically designed to tackle certain fire classes based on these mechanisms. Knowing how they work is essential for using them correctly.
Maintaining Your Fire Extinguishers
It's not enough to simply have the correct extinguishers on hand—regular maintenance and inspection are critical for ensuring their effectiveness in an emergency. At Folgate Safety, we provide:
Annual inspections to check the condition and pressure of your extinguishers.
Replacements or refills when needed.
Advice on the correct placement of fire extinguishers, ensuring compliance with UK regulations.
Additional Fire Safety Services at Folgate Safety
In addition to fire extinguishers, Folgate Safety offers a full range of fire safety solutions to protect your business, including:
Fire alarms: Early detection is key to preventing small fires from turning into larger emergencies.
Fire doors: We install and maintain fire doors designed to contain fires and protect escape routes.
Dry risers: For buildings with multiple storeys, dry risers are essential for providing a water supply to upper floors in case of fire.
We also offer fire marshal training to help ensure that your staff is prepared to handle fire emergencies, perform evacuations, and use fire extinguishers effectively
Conclusion: Choosing the Right Fire Extinguishers for Your Business
Understanding the different types of fire extinguishers and their proper use is essential for maintaining workplace safety and complying with UK fire regulations. Whether you're dealing with Class A, Class B, Class C, Class D, or Class F fires, having the right extinguishers installed and regularly maintained can save lives and property.
At Folgate Safety, we’re dedicated to providing comprehensive fire safety services, including fire extinguisher installation, fire alarms, fire doors, and more. Contact us today to learn how we can help you create a safer work environment through expert advice, equipment, and training.
Ready to upgrade your fire safety systems? Contact Folgate Safety for a consultation on fire extinguisher installation, maintenance, and training to keep your business safe and compliant with UK regulations.
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