Did you know that there are 5 different types of fires? Understanding the different types of fire is a fundamental part of fire safety, as water isn’t a fix-all solution. How a fire behaves is down to the material that is burning and you need to know how to extinguish even the smallest spark.
Fires are grouped into categories known as fire classes. These classifications help people quickly identify the correct method of tackling a fire and the appropriate extinguisher to use. Ready to put your fire marshal hat on? Learn how to respond safely to a fire and avoid actions that could worsen the situation.
How Many Classes of Fire Are There?
We have visited multiple fire and smoke damaged properties to carry out our fire and smoke restoration services. At Cornerstone, we want to educate property owners on all things property related, so that you can feel confident making informed decisions, whether you are dealing with the aftermath of property damage and need professional support or taking proactive steps to prevent issues before they occur.
A common question is how many classes of fire there are. In the UK and much of Europe, fires are divided into five main categories: Class A, Class B, Class C, Class D, and Class F. Each class represents a different type of fuel source and this is what determines how the fire should be extinguished.
The classification system exists because different fuels react differently to heat, oxygen and extinguishing agents. A method that is effective for one type of fire may be dangerous when used on another. Understanding these differences helps ensure the right response is taken in an emergency.
Class A Fire Explained
A Class A fire involves solid combustible materials that typically leave ash after burning. These fires are the most common and are often associated with everyday materials found in homes, office and public buildings. Items such as wood, paper, cardboard, textiles, furniture and certain plastics can all contribute to this type of fire.
When people ask what is a Class A fire, they are referring to fires that start when these common materials ignite and continue burning as long as heat, fuel and oxygen are present.
How To Treat A Class A Fire
Class A fires are usually controlled by removing heat from the fire, which is why water-based extinguishers are commonly used. Water cools the burning material and reduces the temperature enough to stop combustion. Foam extinguishers and dry powder extinguishers can also be used in many situations, as they either smother the fire or interrupt the chemical reaction that allows it to continue burning.
Class B Fires Explained
Class B fires involve flammable liquids rather than solid materials. Substances such as petrol, diesel, paints, solvents and alcohol fall into this category. Because liquids can spread quickly across surfaces, these fires often move rapidly and can be difficult to contain without the correct equipment.
This type of incident is sometimes described as a flammable liquid fire classification, as the burning fuel is a liquid that produces vapours capable of igniting. These vapours can catch fire easily and create fast-moving flames.
How To Treat A Class B Fire
Using water on a Class B fire is dangerous. Water does not mix with many flammable liquids and can cause the burning fuel to spread further. Instead, foam extinguishers are commonly used because they create a barrier that sits on top of the liquid, preventing oxygen from feeding the flames. Carbon dioxide extinguishers and dry powder extinguishers may also be used because they smother the fire and disrupt the combustion process.
Understanding what a Class B fire is helps ensure that you avoid using water and instead rely on extinguishers designed to deal with flammable liquids.
Class C Fire Explained
A Class C fire involves flammable gases. These fires are often associated with industrial environments, gas storage areas, or locations where gas-powered equipment is used. Gases such as propane, butane, methane and liquefied petroleum gas (LPG) can all create Class C fires if they leak and ignite.
When considering what a Class C fire is, it is important to understand that the flames are typically fed by a continuous gas supply. This means the fire may persist until the gas source is turned off.
How To Treat A Class C Fire
Dry powder extinguishers are usually recommended for these fires because they can disrupt the chemical reaction occurring in the flames. However, the safest course of action is often to isolate the gas supply first, as extinguishing the flames without stopping the leak could allow gas to accumulate and potentially create an explosion risk.
Class D Fire Explained
Class D fires involve combustible metals. Although these fires are relatively rare in everyday environments, they can occur in certain manufacturing and industrial processes where metals such as magnesium, titanium, sodium or lithium are present.
Metal fires burn at extremely high temperatures and react differently compared to other fire classes. In many cases, traditional extinguishing methods such as water or foam can actually intensify the fire or cause violent reactions.
How To Treat A Class D Fire
Class D fires require specialised dry powder extinguishers designed specifically for combustible metals. These powders work by absorbing heat and forming a barrier that prevents the metal from reacting with oxygen.
Class F Fire Explained
A Class F fire involves cooking oils and fats, making it one of the most common fire risks in commercial kitchens and restaurants. Deep fat fryers, cooking oils, vegetable oils and animal fats can all cause this type of fire if they overheat and ignite.
Many people ask what Class F fire is, particularly in food preparation environments where hot oil is regularly used. These fires are especially dangerous because cooking oils can reach extremely high temperatures and may continue burning even after the visible flames are extinguished.
How To Treat A Class F Fire
Water should never be used on burning oil because it reacts violently with the hot liquid. When water contacts burning oil, it can instantly turn into steam and eject burning oil into the air, creating a dangerous fireball.
Wet chemical extinguishers are specifically designed for Class F fires. They release a solution that cools the oil and forms a soapy layer on the surface, which seals the fuel and prevents oxygen from feeding the flames.
Why Do Fire Classifications Matter?
Understanding the different types of fire is essential because the fuel involved determines the safest and most effective response. Fire classifications provide a clear system that helps people identify the risk and choose the correct extinguisher quickly.
In workplaces, these classifications are also used to determine which fire extinguishers must be installed and where they should be located. Proper fire safety planning relies heavily on understanding the materials present and the type of fires they could produce.
Why Using the Wrong Extinguisher Is Dangerous
Using the wrong extinguisher can make a fire significantly more dangerous. Some extinguishing agents can react with certain fuels, spreading flames or triggering violent reactions.
For example, water can cause a flammable liquid fire to spread across a wider surface area, while using water on a cooking oil fire can create an explosive flare-up. Similarly, metal fires can react aggressively with water or foam, increasing the intensity of the flames.
Because of these risks, it is essential that the correct extinguisher is used for the specific fire class involved. Fire classification systems exist to guide this decision and reduce the chance of accidents during emergency situations.
Our Managing Director, David Bly, shares his thoughts on how often he sees fire damage made worse by using the wrong extinguisher or response method:
“This is a common aspect in private residences mainly due to the non-recognition of the ignited elements, hence what to put it out with. Our mental ability is to pour water on everything alight, which is extremely dangerous. Fire knowledge is crucial”.
Fire Safety Knowledge Every Property Owner Should Have
Learning about the different types of fire and the different classes of fire is an important step in improving fire safety awareness. From Class A fires involving everyday combustible materials to Class F fires caused by cooking oils and fats, each fire classification requires a different response and the correct type of extinguisher.
At Cornerstone, we believe property owners should feel confident managing risks within their buildings. If you have experienced property damage caused by fire or want guidance on how to protect your property and prevent future damage, our team is here to help. Get in touch with Cornerstone today to learn how we can support your property with expert advice and restoration services.
