Introduction to fires
In this article, we will try in a simple way to understand what fire is and how it can be dealt with. Naturally, we are talking about a vast subject which we will initially approach in a superficial manner.
First, let’s look at some definitions in the simplest possible terms.
What is combustion, what is fire, and what is a wildfire?
• Combustion is the chemical reaction of an element or a chemical compound with oxygen, which is accompanied by the production of heat and light.
• Fire is combustion that is accompanied by a flame.
• Wildfire is an uncontrolled fire, caused by unregulated combustion with oxygen, and it involves the release of large amounts of heat and light.
However, for fire to exist, three factors must be present — the well-known "fire triangle":
Fuel – Oxygen – Heat
If even one of these three factors is missing, fire cannot occur.
In order for the fire to be sustained, a chain chemical reaction is created, and this is referred to as the fire tetrahedron.
Therefore, in order to extinguish a fire, we must deprive it of one or more of the above factors:
Lower its temperature by cooling it down, e.g., with water.
Remove part or all of the fuel, e.g., using an excavator to create a firebreak.
Cut off the oxygen supply, e.g., by using a fire blanket.
Interrupt the chain chemical reaction, e.g., by using a special fire extinguisher.
Now that we've seen what fire and wildfire are, let's move on to the categories of fire.
Fires are classified based on the type of fuel involved. This categorization helps us better understand how to deal with each type and determine which fire extinguisher is suitable for each case.
Fire Categories
Class A: Fires involving solid fuels such as paper, wood, plastics, etc.
Class B: Fires involving liquid fuels such as gasoline, diesel, etc.
Class C: Fires involving gaseous fuels such as propane, butane, natural gas, etc.
Class D: Fires involving metals such as potassium, magnesium, etc.
Class F: Fires involving oils and fats, such as cooking oils and grease.
In a follow-up article, we will go deeper into the methods of handling and extinguishing fires depending on their category.
