What is meant by the Lower Explosive Limit (LEL)?

The Lower Explosive Limit (LEL) refers specifically to the minimum concentration of a fuel in the air needed for combustion to occur. If the concentration of fuel in the air is below this threshold, the mixture is too lean to ignite, no matter the heat or ignition source present. This concept is crucial for safety in handling volatile substances, as working with concentrations below the LEL ensures that an explosion or fire is improbable.

Understanding the LEL is essential for safety management, particularly in industrial settings where flammable gases and vapors may be prevalent. Ensuring that the concentration of these substances remains above the LEL can help prevent unintentional ignition and, consequently, protect lives and property from potential fire hazards.