What is one of the three necessary items for a fire to occur?

Fuel is one of the three essential components for a fire to ignite and sustain itself. The fire triangle illustrates this concept, showing that fire requires three elements: heat, fuel, and oxygen. Fuel can be any combustible material, such as wood, paper, or gasoline, that can undergo combustion when it reaches its ignition temperature. Without fuel, a fire cannot start or continue to burn, regardless of the presence of heat and oxygen.

In contrast, the other options do not provide the necessary conditions for a fire. Metal and glass are generally not considered fuel sources; while they may conduct heat or be used in various processes, they do not facilitate combustion. Water, while often used to extinguish fires, does not contribute to the fire's ignition. Understanding the importance of fuel helps ensure proper fire prevention strategies are in place in any shop environment.