What must be present for a fire to continue to burn?

For a fire to continue to burn, a chain reaction must be present as part of the fire's combustion process. This chain reaction is often referred to in the context of the fire tetrahedron, which consists of four elements: heat, fuel, oxygen, and a chemical chain reaction. The chain reaction allows the fire to sustain itself once it has started by enabling the continued release of energy and the production of heat to maintain the fire.

While an ignition source and a fuel source are necessary to start the fire, they are not sufficient alone for the fire to continue burning. After initial ignition, the fire must have a stable chain reaction to sustain combustion. Water is not a component that supports combustion; in fact, it is typically used to extinguish fires by cooling the fire and cutting off the chain reaction through dilution or removal of heat.

Understanding the need for a chain reaction is crucial for fire prevention and control strategies, as interrupting any part of this cycle will help to extinguish the flames.