What does a chemical's "Explosive limit" depend on?

The explosive limit of a chemical primarily depends on concentration. This concept refers to the specific range of concentrations of a flammable substance in the air that can support combustion or an explosion. If the concentration is below the lower explosive limit (LEL), the mixture is too lean to ignite. Conversely, if it is above the upper explosive limit (UEL), the mixture is too rich. Within this range, the chemical can react with the air and result in an explosion when an ignition source is present.

While factors like temperature, volume, and pressure can influence the behavior and reactivity of chemicals, they do not directly define the explosive limit itself. For example, changes in temperature can affect the pressure and potentially alter the concentration of gases, but the primary designation of what constitutes the explosive limits is strictly about the concentration ratios of the flammable material and the oxidizer. Understanding this distinction is crucial for any safety protocols and handling procedures related to hazardous materials.