What is LEL?

What is LEL?

• A. Lower Explosive Limit
• B. Leading Exposure Level
• C. Limited Explosive Level
• D. Lower Exposure Limit

Answer: (D)

LEL stands for Lower Explosive Limit, the minimum concentration of a flammable gas or vapor in air that can ignite in the presence of an ignition source. It marks the lean end of the flammability range; ignition can occur only when the mixture is between the LEL and the upper explosive limit (UEL). For example, methane has a LEL around 5% and a UEL around 15%; below 5% there isn’t enough fuel to ignite, between 5% and 15% ignition is possible, and above 15% the mixture is too rich to ignite. Gas detectors often report percent LEL to show how close the environment is to the flammable limit. The term “Lower Exposure Limit” isn’t the standard term for flammability limits.

LEL stands for Lower Explosive Limit, the minimum concentration of a flammable gas or vapor in air that can ignite in the presence of an ignition source. It marks the lean end of the flammability range; ignition can occur only when the mixture is between the LEL and the upper explosive limit (UEL). For example, methane has a LEL around 5% and a UEL around 15%; below 5% there isn’t enough fuel to ignite, between 5% and 15% ignition is possible, and above 15% the mixture is too rich to ignite. Gas detectors often report percent LEL to show how close the environment is to the flammable limit. The term “Lower Exposure Limit” isn’t the standard term for flammability limits.