Previous Lesson

Fire

FIRE:

Fire is a “Triangle.” If one of the three required elements is removed, there is no longer fire.

The three elements of fire are:

1. Fuel

2. Oxygen

3. Heat

 

1. Fuel

Fires are classified by the type of fuel they burn. Fuel is everywhere but it requires oxygen and heat to burn.

  • Anything that will burn
  • Paper, wood, cardboard, plastic, etc.
  • Fabric
  • Electrical equipment/wires
  • Flammable liquids
  • Cleaning material
  • Gases and fumes

 

2. OXYGEN

Oxygen is everywhere and cannot be easily controlled. Most fires are extinguished by removing the oxygen. This can be accomplished using something simple, such as:

  • Pouring baking soda over a small stove fire
  • Using an appropriate fire extinguisher (best approach)

 

3. HEAT

Heat is the most readily controlled part of the fire triangle.

But heat, to include a spark or a chemical reaction, is how all fires start.

Heat sources include:

  • Smoking-Material
  • Open flames
  • Heat producing equipment (coffee maker)
  • Faulty/overloaded electrical equipment or wiring
  • Power tools
  • Friction
  • Sparks

 

TYPES OF FIRES

Which type of extinguisher should I use? First recognize that there are four different kinds of fires, and fires are

classified by the type of fuel they burn. Depending on the

type of fuel that is burning, this will determine what fire extinguisher will be used.

 

  • Class A fires: Are ordinary combustible materials like burning paper, wood, rags, plastic etc.
  • Class B fires: Involve flammable or combustible liquids such as gasoline, oil, grease and paint.
  • Class C fires: Involve energized electrical equipment, such as office equipment, outlets, motors, power tools and heaters. Water is a particularly dangerous extinguishing medium for class C fires because of the risk of electrical shock.
  • Class D fires: Involve combustibles metals, such as magnesium, aluminium, potassium and sodium. These material burn at extremely high temperatures and will react violently with water, air and/or other chemicals. Class D fires are usually found only in industrial settings and should be extinguished with a dry powder chemical only.

 

NOTE:

Some fire may be a combination of these.

Your fire extinguisher should have an ABC rating on it. These ratings will often have numbers like 3-A:40-B:C. higher numbers mean more fire fighting power. In this example, the extinguisher has a good fire fighting capacity for class A, B, and C fires.