What is Fire?

Fire is a series of chemical chain reactions that break fuel down into pieces and result in waste products of carbon dioxide, carbon monoxide, water vapor, unburned fuel or smoke, and other chemicals. 

You can stop a fire in the following ways:

  • remove the heat source (dousing with water, for example)
  • cut off the oxygen (such as putting a lid on burning grease)
  • use extinguishing chemicals (such as those found in fire extinguishers)

The table on the right shows the four classes of fire, with examples of each below:

Flames flaring up in a restaurant cooking area
Class A burn of cardboard boxes
Class B burn of flammable liquids, with automatic sprinklers activated overhead