What does the Lower Explosive Limit (LEL) indicate?

The Lower Explosive Limit (LEL) is a critical concept in understanding explosion hazards, as it refers to the minimum concentration of a flammable gas or vapor in the air that is capable of igniting when an ignition source is present. This means that if the concentration of the gas falls below this level, it is too "lean" to sustain a combustion reaction, and therefore, no explosion or fire will occur.

By identifying the LEL, safety personnel can effectively monitor and control hazardous environments, ensuring that concentrations remain above this threshold to prevent potential ignition. In practical terms, knowing the LEL helps in assessing risks in various industrial and operational settings, promoting safe handling, storage, and use of flammable substances.