What is the difference between the upper and lower flammable limits of a gas or vapor called?

The term that describes the difference between the upper and lower flammable limits of a gas or vapor is referred to as the flammable (explosive) range. This range indicates the concentrations of a substance in the air that are capable of supporting combustion. The lower flammable limit is the minimum concentration of vapor in the air below which the mixture is too lean to ignite, while the upper limit is the maximum concentration above which the mixture is too rich to ignite. Understanding this range is crucial when working with flammable gases and vapors, as it helps in assessing the potential risk of fire or explosion in different environments. Identifying this range is vital for safety precautions and effective hazard analysis in various industries dealing with hazardous materials.