Posted by Arowosegbe Olawale in General

The Chemistry of Fire

At its core, fire is a chemical reaction that involves the rapid oxidation of a fuel source in the presence of oxygen, resulting in the release of heat, light, and various combustion byproducts. To comprehend fire behavior, it is crucial to grasp the chemical elements at play.

The Fire Triangle: The fire triangle represents the three essential components required for a fire to occur: fuel, oxygen, and heat. When these elements are in the right proportions, a fire can sustain itself. Removing any one of these elements can extinguish a fire.

The Fire Tetrahedron: Building on the fire triangle, the fire tetrahedron adds a fourth component: the chemical chain reaction. This chain reaction is necessary to sustain the fire and propagate it. Breaking this reaction is crucial for fire suppression.

Classification of Fires

Fires are classified based on the type of fuel involved. This classification system is essential for determining the appropriate fire suppression methods and agents. Common classifications include:

• Class A Fires: These involve ordinary combustibles such as wood, paper, and textiles.

• Class B Fires: These fires result from flammable liquids like gasoline, oil, and solvents.

• Class C Fires: Electrical fires where the fuel source is energized electrical equipment.

• Class D Fires: Fires involving combustible metals like magnesium and titanium.

• Class K Fires: Kitchen fires caused by cooking oils and fats.

Fire Growth and Development

Understanding how fires grow and develop is vital for designing effective fire protection systems. Fires typically progress through four stages: incipient, growth, fully developed, and decay. Each stage has distinct characteristics and poses different challenges for suppression.