What term is often used interchangeably with flammability range?

What term is often used interchangeably with flammability range?

• A. Ignition limit
• B. Flash point
• C. Explosive limit
• D. Autoignition temperature

Answer: (C)

Flammability range is the window of fuel–air concentrations where a mixture can ignite and sustain flame when a source of ignition is present. The term explosive limits is often used interchangeably with this range because it describes the same boundary: the lower limit below which the mixture is too lean to burn and the upper limit above which it’s too rich to burn. Together, they define the concentration range in which ignition can lead to flame propagation or an explosion in the right conditions.

The other terms don’t fit as well. Ignition limit is sometimes used to refer to the concentration needed to start burning, but it’s not as commonly used to describe the full range. Flash point is about the minimum temperature for a liquid’s vapor to ignite, not the concentration in air. Autoignition temperature is the temperature at which something will ignite without an external flame, also not about the fuel–air concentration.

So, the best term to describe the same concept as the flammability range is explosive limits.