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The Fire Triangle | A Simple Guide

The Fire Triangle
 

What is the Fire Triangle?

 

The fire triangle is a simple method designed to show how a fire ignites and spreads. It includes three components required to ignite and sustain a fire, oxygen, heat and fuel. A fire can only be sustained if all three of these components are still active, if one is removed from the equation, the fire will extinguish.


Commonly referred to as the combustion triangle, this concept outlines the fundamental elements that drive the chemical reactions responsible for igniting and sustaining fires. With this understanding, if a fire breaks out in your workplace, you'll be well-equipped to manage and extinguish it safely.


The fuel, oxygen and heat together cause a chain reaction and can create a high level of destruction if not dealt with quickly and safely. This can be done by covering the fire with a blanket to remove the oxygen, however larger fires are a lot more difficult to control as oxygen cannot be removed in such large spaces.

 

 

3 Elements of the Fire Triangle

 

The 3 elements of the fire triangle combine to ignite and sustain a fire. It is important to learn about each individual component to help prevent fires in the workplace and also control one if it ignites. The 3 elements include:


Oxygen

The earth’s atmosphere is only made up of 21% oxygen but this is enough to ignite a fire and even sustain it, so long as it still has the two other elements. Oxygen or an oxidising agent causes the combustion reaction and reacts with the burning fuel to release CO2 and heat.


Open windows, doors and air vents are all sources of oxygen and it is impossible to completely remove the hazard of oxygen in workplaces as we need oxygen to breathe. However, it can be removed in small spaces with small fires with the use of fire blankets or fire doors for larger fires.


Fuel

The fuel for a fire is any material that is flammable or combustible which burns and will keep on burning until the fire is extinguished.


This can be in the form of a solid, liquid or gas and includes:


  • Wood

  • Paper

  • Textiles

  • Cooking oils


The fuel’s ability to burn will depend on the temperature and the size, shape, moisture content and quantity of the material. Workplaces such as offices and warehouses and homes all contain a range of flammable materials and it can be difficult to remove all hazards to prevent fires.

 

Heat

All materials have a certain flash point which means the lowest temperature at which they are able to ignite. A heat source is required to complete the triangle and cause a fire and these can include:


  • Hot surfaces

  • Sparks from faulty electrical equipment

  • Open flames

  • Friction

  • The sun


As combustion reactions burn, they also produce heat which increases the temperature even further. The heat in some fires can be reduced by adding water to it but this isn't suitable for all types of fires such as electrical fires as water will help to spread this fire by conducting electricity.


There are different types of fire extinguishers available for all types of fires including water, foam, dry powder, CO2, wet or dry chemical and clean agent. It is vital that you use the right fire extinguisher for the type of fire.

 

 

The Fire Tetrahedron

What is a Fire Tetrahedron?

 

The fire tetrahedron combines the three components of the fire triangle, fuel, heat and oxygen, and adds one more component, the chemical chain reaction. This turns the fire triangle into a three dimensional pyramid shape, which represents these four components that are required to ignite and sustain a fire, with the chemical reaction of the three elements.


The chemical chain reaction occurs once a fire has started and helps to sustain the fire until one of the components is effectively removed by a fire extinguisher, fire blanket or other method. Foam is used to remove the oxygen, water can lower the temperature and some gases can also be used to create a barrier and stop the chemical reaction.


A fire is unable to sustain itself without this fourth component of a chemical chain reaction and if it is interrupted, the fire will become controllable and will be able to be safely dealt with.

 

 

Two Fire Extinguishers

How to Break the Fire Triangle

 

If a fire occurs in the workplace or at home, it is vital that you remove one or more of the components from the triangle in order to control and extinguish the fire. This is also helpful in preventing the fire from igniting in the first place and will help to prevent the spread of the fire.


There are different methods available depending on which component of the fire triangle you wish to eliminate.


Oxygen Removal

Oxygen is an important component of the fire triangle as it is required to sustain fires. Therefore it can be difficult or sometimes even impossible to remove with big fires in open spaces, but it is possible to remove in the case of small spaces and small fires.


Depending on the type of fire, you are able to remove oxygen from fires using a water, foam or CO2 fire extinguisher or use fire blankets for smaller kitchen fires to eliminate the oxygen and extinguish the fire.


Fire doors can also be used to prevent the spread of fire and effectively remove oxygen from a larger space in workplaces. Workplaces must provide the correct fire extinguisher depending on the type of fire most likely to be caused due to the nearby materials and equipment.

 

Heat Removal

Fire also needs heat to sustain itself and when you remove the heat source, the fire can be easily extinguished and even prevented in some cases. The most effective method of removing the heat source is by using water. A water extinguisher will remove the heat safely for many fires in the workplace and at home.


However, water isn't a suitable substance to use on certain fires such as cooking and electrical fires and so to remove the heat source, you must use the correct type of extinguisher such as wet chemical or CO2 which will suffocate the fires and prevent re-ignition. Another way of removing the heat source is by using large gusts of air to reduce the temperature.

 

Fuel Removal

It should be a priority to try and prevent a fire from igniting in the first place which means removing any flammable materials from a heat source as well as incorporating fire resistant materials on the premises if possible. This can include fire resistant office furniture, clothing and building materials which will prove to be effective in reducing and preventing fires.

 

 

Man using Fire Extinguisher

Workplace Responsibilities


Under The Regulatory Reform (Fire Safety) Order 2005, employers are responsible for implementing fire safety measures, Risk Assessments, and records of fire safety equipment and maintenance. Along with knowledge of the fire triangle, workers should learn how to use fire safety equipment such as fire extinguishers, fire blankets and fire doors. You should also learn what the different fire safety signs mean and receive regular fire drills to ensure workers know where the fire escapes and meeting points are for each building.


Removing one or more of these three components in the fire triangle will prevent ignition and will also stop any fires from spreading. It is important that all employees learn about the fire triangle and receive appropriate fire safety training to ensure everyone stays safe in the event of a fire.


 

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