What Does Lower Explosive Limit (LEL) Mean?
A lower explosive limit (LEL) refers to the minimum concentration of a combustible vapor that is required to facilitate its combustion in air. Knowing the LEL of a substance is important for safety reasons, especially for hazardous substances.
The lower explosive limit may also be known as the lower flammability limit (LFL).
Corrosionpedia Explains Lower Explosive Limit (LEL)
Below the lower explosive limit (LEL) the substance possesses an insufficient concentration to ignite in air relative to the amount of oxygen in the atmosphere.
The corresponding higher limit, where the vapor concentration is at its maximum to support combustion, is known as the upper explosive limit (UEL). The range of concentration between the LEL and the UEL is known as the flammability range of a gas, which is the concentration volume that can be ignited due to its relative concentration compared to oxygen in the atmosphere.