The term "LEL" in gas terminology stands for what?

The term "LEL" stands for Lower Explosive Limit, which is a critical concept in gas safety. The Lower Explosive Limit is the minimum concentration of a gas in air below which propagation of flame does not occur in a given environment. Understanding LEL is essential for ensuring safety when dealing with flammable gases, as it helps workers assess the risk of ignition.

For example, if the concentration of a flammable gas is at or below the LEL, the mixture is too "lean" for combustion to occur. Conversely, if the concentration exceeds the LEL, there is a sufficient amount of gas present in the air to create a potentially hazardous situation. This concept is vital in various industries, including HVAC and gas utilities, where monitoring gas concentrations can prevent dangerous situations from developing.

The other terms presented do not accurately describe the significance of LEL in gas terminology, making "Lower Explosive Limit" the correct and relevant choice.