By most standards including the International Fire Service Training Association (IFSTA) there are 4 stages of a fire. These stages are incipient, growth, fully developed, and decay. The following is a brief overview of each stage.
Incipient – This first stage begins when heat, oxygen and a fuel source combine and have a chemical reaction resulting in fire. This is also known as “ignition” and is usually represented by a very small fire which often (and hopefully) goes out on its own, before the following stages are reached. Recognizing a fire in this stage provides your best chance at suppression or escape.
Growth – The growth stage is where the structures fire load and oxygen are used as fuel for the fire. There are numerous factors affecting the growth stage including where the fire started, what combustibles are near it, ceiling height and the potential for “thermal layering”. It is during this shortest of the 4 stages when a deadly “flashover” can occur; potentially trapping, injuring or killing firefighters.
Fully Developed – When the growth stage has reached its max and all combustible materials have been ignited, a fire is considered fully developed. This is the hottest phase of a fire and the most dangerous for anybody trapped within.
Decay – Usually the longest stage of a fire, the decay stage is characterized a significant decrease in oxygen or fuel, putting an end to the fire. Two common dangers during this stage are first – the existence of non-flaming combustibles, which can potentially start a new fire if not fully extinguished. Second, there is the danger of a backdraft when oxygen is reintroduced to a volatile, confined space.
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Stages of Fire |
Types of Fire?
Types of Fire - The 5 Fire Classifications
It is very important to understand the five different classifications, or types of fire. As fires are classified according to the type of fuel that is burning if the wrong type of fire extinguisher is used, a dangerous situation may arise. We offer a range of fire suppression systems for all types of fire.
It is very important to understand the five different classifications, or types of fire. As fires are classified according to the type of fuel that is burning if the wrong type of fire extinguisher is used, a dangerous situation may arise. We offer a range of fire suppression systems for all types of fire.
Class A type fires involve combustible materials like wood, paper, textiles, straw, coal, car tyres. They are often found in commercial and home buildings. -
Class B type fires are caused by combustion of liquids or materials that liquify for example fats, oils, petrol, paints alcohol and parraffin.
Class C type fires are caused by combustion of gases for example: hydrogen, natural gas, methane, propane and acetylene.
Class F fires involve combustible oils and grease commonly found in commercial kitchens. The new cooking formulations used for commercial food preparation require a special wet chemical extinguishing agent that is specially suited for extinguishing these hot fires that have the ability to re-flash. Never use other pressurised extinguisher types, as water, foam, powder or CO2 on burning cooking oil, as the pressure jet might carry the burning oil and spread the fire!