Construction Skills Certification Scheme (CSCS) Test 2025 – 400 Free Practice Questions to Pass the Exam

The initiation of a fire requires three essential components, often referred to as the fire triangle: heat, fuel, and oxygen. Among the options provided, fuel and oxygen are the correct elements necessary alongside heat for a fire to start.

Fuel is any combustible material, which can include a wide range of substances such as wood, paper, gasoline, or other flammable materials. Oxygen, typically found in the air, is crucial because it supports the chemical reaction that fuels the fire. Without oxygen, a fire cannot sustain combustion, regardless of the presence of heat and fuel.

So, the combination of fuel and oxygen, along with an initial heat source, creates the conditions required to ignite and sustain a fire. Other options, such as water and gas, may influence fire behavior but cannot initiate a fire on their own. Similarly, wood and paper are types of fuel but do not encompass the broader category of what can serve as fuel. Lastly, heat and smoke are related but do not meet the criteria since smoke is a byproduct of combustion, not a factor that initiates it.