Fire triangle – Fire Tetrahedron in Detail

Basic safety starts from understanding what is fire triangle and What fire triangle consists of? This article is all about what three ingredients are required to ignite a fire.

Industrial safety has now become a key factor for industries and a point of focus. Now without industrial safety policies, it is not possible for industries to survive as now Government is becoming strict in terms of safety in chemical industries hence now it’s mandatory for industries to improve their safety standards to remain in existence.

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Fire triangle concept

What is Fire?

A Fire is the rapid oxidation of a material (fuel) in the exothermic chemical process of combustion, which releases heat, light, and various reaction products. (Sorce – Wikipedia)

In any chemical industry, fire hazard is very common and most of the material, chemical or solvents used in the chemical industry used for the manufacturing of the product have a potential for fire hence there is always a risk of fire in chemical industry.

But considering the risk of fire, we can not close the industry on contrary, we need to reduce the risk of fire. To understand the cause of fire there is a concept by name Fire triangle. Let us learn in detail,

What is Fire Triangle – What fire triangle consists of?

The fire triangle is a model that consists of three elements which are the basis requirement for fire to be established. This fire triangle is also known as the combustion triangle of the fire behavior triangle. This fire triangle model consists of Fuel, ignition, and oxygen. According to this model, if these elements i.e. Fuel oxygen is present in the right proportion get ignition then the fire will occur.

Three elements of Fire triangle –

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fire triangle drawing
  1. Fuel
  2. Oxygen
  3. Ignition

1. Fuel

Fuel can be considered the primary element for the establishment of fire. Fuel is the element that will burn and result in the fire. The quantity of fuel will decide the duration of the fire. E,g, of fuel can be any flammable material i.e. wood, paper, dry grass, solvents, plastic, petroleum products like petrol, diesel, gasoline natural gas, etc.

2. Oxygen / oxidizing agent

Oxygen is an element whose presence is important for fire. when fuel is burned, it reacts with oxygen and results in the generation of released heat and generates combustion. E.g. of oxidizing agents are fluorine gas, perchlorate salts such as ammonium perchlorate, or chlorine trifluoride, etc.

3. Ignition / Heat

All the flammable substances had flashpoints. Ignition in the form of spark or heat is one of the three elements of the fire triangle. If in an area there is fuel stored the atmosphere in the room has sufficient oxygen present and in this condition, if the flammable substage gets ignition or heat, it may result in fire.

Fire tetrahedron

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Now you had learned what is fire triangle which consists of three elements. Eventually, the fire triangle has been updated to fire tetrahedron on the addition of the fourth element to the fire triangle i.e. chain reaction.

Initially, the occurrence of fire was represented by the fire triangle which is consisting of Fuel, heat, and oxidizing agent/ oxygen but later on additional element had been introduced to the Fire triangle and that was a chain reaction and this concept of Fire tetrahedron came into existence. 

The additional element to the fire triangle is an uninhibited chemical chain reaction the significance of a chemical chain reaction is it provides sufficient exothermic reaction energy to produce ignition. The fuel/air ratio must be within flammable limits, which describes the amount of vapor in the air necessary to propagate flame. Removing any of these four factors will prevent, suppress, or control the fire.

Uses of fire triangle – Uses of fire tetrahedron

The fire triangle will help you to understand the possibility of occurrence of fire which will help to design process safety. The fire triangle is the base of the fire extinguisher which works to eliminate one of the fire elements and extinguish the fire.

Example of use for fire triangle – Consider there is a wood block present in ground and due to any reason fire broke out in it. As wood is a flammable material, one of the fire triangles is present, now it is present in the open ground so it will get oxygen from the atmosphere (Atmosphere consists of 21% oxygen) and here consider fire/ignition has been provided purposefully.

All these elements complete fire triangle and result in fire in the wood block. Now to extinguish fire we have to remove either of the element from the fire triangle. If we simply put the blanket over for wood (Consider the fire is not widely spread then then blanket will isolate the oxygen from the fire which will break the fire triangle and in this way we can suppress the fire.

On the same basis, fire extinguisher works. there are different types of fire extinguishers and the types of fire extinguishers are described below

  1. Water
  2. Powder
  3. Foam
  4. CO2
  5. Wet chemical

All these fire extinguishers work on the same principle which is to break the fire triangle by eliminating one of the components of the fire triangle. We has posted a detailed article on Types of fire extinguishers in which we had also included the use and technique.

In the chemical industry, job works are conducted every single day like preventive maintenance of equipment or equipment replacement. To ensure a safe working environment and safety at workplace, as a part of industrial safety, a work permit system has been followed. Especially to determine and reduce the risk of industrial fire accidents Hot work permit system has been followed work permit system in chemical industry.

FAQ (Uses of fire triangle)

1. What are the 4 elements of fire tetrahedron?

The four elements of fire tetrahedron are Fuel (material) Oxygen (oxidizing) and Ignition (spark) and chain reaction which continue the fire.

2. What three ingredients are required to ignite a fire?

The three ingredients of fire are Fuel (material) Oxygen (oxidizing) and Ignition (spark).

3. What is the percent oxygen for a fire to burn?

Atleast 16 percent of oxygen is required for a fire. Air contains more than 21 percent oxygen.

4. is oxygen flammable?

No, oxygen is not flammable but an oxidizing agent. It helps other flammable materials to burn.

Wrapping Up

Hope you like the article on what is fire triangle and what tetrahedron consists of fire triangle definition and what fire triangle is consists of. If you had any points that you are not able to understand the fire triangle concept then feel free to use the comment section and if you had any value addition point over this topic we welcome your suggestion.

Me - Founder of Chemical Tweak - A Chemical Engineer by profession and a part-time self-trained technology blogger.

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