Blaze Through the 2026 CPS Firefighter Exam – Ignite Your Career!

The term Limiting Oxygen Concentration refers to the lowest level of oxygen in an atmosphere where combustion can occur. When the concentration of oxygen falls below this threshold, it becomes insufficient to sustain combustion, meaning that fires or explosions cannot ignite or continue to burn. This concept is crucial in various fire safety and hazard analysis contexts, helping to determine safe environments for handling flammable materials.

The other options provide different contexts around oxygen and combustion but do not correctly define Limiting Oxygen Concentration. For instance, the requirement for oxygen for all combustion speaks more to the overall need for oxygen, while the combination of oxygen and fuel that supports combustion refers to the fundamental principle of fire behavior. The idea of a maximum oxygen level for explosive materials is also distinct from Limiting Oxygen Concentration, which specifically addresses the minimum usable concentration for sustaining a fire. Thus, the selected answer accurately captures the essence of what Limiting Oxygen Concentration signifies in fire dynamics and safety.