Which term describes the range in concentration between the lower and upper flammable limits?

The term that describes the range in concentration between the lower and upper flammable limits is known as the "flammable range." This term refers specifically to the spectrum of concentrations of a flammable substance in air, wherein a mixture can ignite and sustain combustion when exposed to an ignition source.

The lower flammable limit (LFL) is the minimum concentration of a substance in air that can support combustion, while the upper flammable limit (UFL) is the maximum concentration above which the mixture is too rich to ignite. Therefore, the flammable range encompasses all concentrations between these two limits, highlighting the conditions under which fires can start and propagate. Understanding this range is crucial for fire fighters and hazardous materials responders to effectively manage and mitigate potential fire hazards.

In contrast, other terms such as combustion zone and ignition range do not specifically define the range of flammable concentrations. The term explosion factor generally refers to the potential for an explosive reaction in a specific context, which is not the same as defining the concentration limits for combustion. Thus, identifying the flammable range is essential for evaluating and controlling fire risks.