The fire triangle is a model that represents the three ingredients needed for the chemical reaction of fire, or combustion, to occur.
What You Need To Know
- Oxygen, heat and fuel make up the fire triangle
- Fuels in wildfires can be anything from grasses to large trees
- Winds supply a steady flow of oxygen to sustain fire growth
- A 10% uphill grade makes a fire spread two times faster
The three elements that make up the fire triangle are heat, fuel and oxygen. Each one of these elements make up the three sides of a triangle.
If you take away one of these elements, or sides, you would not have a triangle. The same holds true for fires.
Without heat, fuel and oxygen, fires can’t sustain themselves.
You need heat or some ignition source to start a fire. The most common natural ignition source of heat in California is lightning.
Man-made heat sources can range from a cigarette butt to a spark from an electrical power line.
Heat allows fire to spread by drying nearby fuels and the air near the flame. Think of a forest fire on a mountain slope.
Because heat rises, trees and shrubs above the flame dry out and become easier to burn.
A 10% uphill grade will make a fire burn two times faster because the heat above a flame dries out the fuel source. This allows the uphill fuels to dry out faster and burn more rapidly.
The next element in the fire triangle is the fuel source. Fuel is any kind of material that will burn.
This can be anything from grasses to large trees and timber. Fuels are characterized by how much moisture is present to sizes, shapes, and quantity.
Thin dry fuels such as grasses can ignite very easily and burn quickly. Large trees, on the other hand, take longer to ignite, but burn much more intensely.
The last side of the fire triangle is oxygen. Air is made-up of about 21% oxygen, 78% nitrogen and less than 1% other gases including carbon dioxide and water vapor.
Fire only needs about 16% oxygen to burn. Without oxygen, fires won't burn.
Water vapor in the air, or high relative humidity values, help to keep fuel sources moist. This helps slow the spread of fires and hinders ignition of fires.
When conditions are windy, the oxygen supply near a fire keeps getting replenished. The extra oxygen supplied by wind helps a fire burn more intensely.
To recap, in order for combustion (chemical reaction of fire) to take place you need three elements to work together. These elements are fuel, heat and oxygen. These three elements make up the fire triangle.
FAQs
Oxygen, heat, and fuel are frequently referred to as the "fire triangle." Add in the fourth element, the chemical reaction, and you actually have a fire "tetrahedron." The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.
What are the 3 elements present for a fire to burn? ›
The 3 things a fire needs are heat, fuel and oxygen. These three elements work together to help a fire start and take over.
What are the 3 main elements that can cause a fire? ›
The fire triangle is a simple way of understanding the elements of fire. The sides of the triangle represent the interdependent ingredients needed for fire: heat, fuel and oxygen.
What are the 3 components needed for a fire? ›
It focuses on the three core elements that are needed for a fire to thrive, which are heat, oxygen and fuel.
What are the 3 things you need to make fire? ›
There are three things that have to be present for any fire to burn – heat, fuel and oxygen. If any one of these things is removed, the fire will go out.
Where are the 3 elements of fire? ›
Oxygen, heat, and fuel are frequently referred to as the "fire triangle." Add in the fourth element, the chemical reaction, and you actually have a fire "tetrahedron." The important thing to remember is: take any of these four things away, and you will not have a fire or the fire will be extinguished.
What are the 3 main steps of fire? ›
Traditional Fire growth in a room can be divided into three distinct stages: the growth stage (incipient), the fully developed stage (free-burning), and the decay stage (smoldering).
What are the 3 factors causing fire? ›
Imperfect/loose wiring, faulty/old equipment and overloaded sockets are just a few examples that can cause sparks or overheating and thus fire.
What are the three elements needed for a fire quizlet? ›
The fire triangle, is the oldest and simplest model that shows three elements necessary for combustion to occur, OXYGEN, FUEL AND HEAT.
What are the 3 most common types of fires? ›
Class A: solid materials such as wood or paper, fabric, and some plastics. Class B: liquids or gas such as alcohol, ether, gasoline, or grease. Class C: electrical failure from appliances, electronic equipment, and wiring.
Heat, fuel and oxygen must combine in a precise way for a fire to start and continue to burn. If one element of the fire triangle is not present or removed, fire will not start or, if already burning, will extinguish.
What are three essential requirements for fire? ›
The three essential requirements to produce fire are:
Basic Fire Suppression
The fire triangle is a graphic representation of the three components that must be present for combustion to occur: 1) fuel, 2) heat, and 3) oxygen. If some of these components are removed or sufficiently reduced, combustion ceases.
What are three things needed to keep a fire burning? ›
The fire triangle is a symbol that shows the three things that are required for a fire to burn, namely:
" Assuming the occupants were already safe, I'd save my photo albums, my computer, and my gun. " "My dog, my computer, and my pictures." "That's a toughie. My pictures, wallet, and binder with all my important papers, I think."
Why is fire an element? ›
The ancient Greeks and alchemists thought that fire was itself an element, along with earth, air, and water. However, the modern definition of an element relates to the number of protons a pure substance possesses. Fire is made up of many different substances, so it is not an element.
What are the 3 fuels of fire? ›
The three ingredients of a fire triangle are; heat, fuel and oxygen. See if Fire Action can help your business. Get in touch with our team to find out more.
What are the 3 elements fire extinguisher? ›
The three key elements a fire requires to flourish are heat, fuel and oxygen, all fire extinguishers work by removing one or more of these 3 key elements. Please refer to the fire combustion triangle for a clear understanding of the combustion process.
What are the three chemical reactions in fire? ›
Fire is a chemical chain reaction which takes place with the evolution of heat and light. In order for a fire to take place there are 3 main ingredients that must be present: Oxygen, Heat and Fuel. In chemistry we call the type of reaction that produces fire a combustion reaction.
What are the chemical elements that burn? ›
Oxidants for combustion have high oxidation potential and include atmospheric or pure oxygen, chlorine, fluorine, chlorine trifluoride, nitrous oxide and nitric acid. For instance, hydrogen burns in chlorine to form hydrogen chloride with the liberation of heat and light characteristic of combustion.
