Question 1027 Deck General

The correct answer is D) the temperature at which no spark or flame is required to ignite gas or vapor. Auto-ignition temperature, also known as self-ignition temperature, is the minimum temperature required for a substance to spontaneously ignite and undergo combustion in the absence of a spark or flame. This temperature is an important property to consider when handling flammable materials, as it indicates the point at which they can ignite without an external ignition source. The other options are incorrect because they do not accurately describe the auto-ignition temperature. Option A refers to the explosive limit of a fuel-air mixture, option B describes the temperature at which a fuel begins to produce flammable vapors, and option C describes the temperature at which a fuel will continue to burn once ignited, but none of these directly address the temperature required for spontaneous ignition.