What is the lowest temperature at which a fuel-air mixture will ignite spontaneously called?

The lowest temperature at which a fuel-air mixture will ignite spontaneously is known as the auto-ignition point. This is the temperature where the fuel can ignite without an external ignition source, such as a flame or spark. Understanding the auto-ignition point is critical for firefighting and safety, as it helps in assessing the risk of fire hazards in various environments.

Other terms like flash point refer to the lowest temperature at which a liquid can produce enough vapor to ignite with an external flame, but it does not involve spontaneous ignition. The concept of ignition temperature is similar but generally refers to the temperature needed for a substance to ignite in the presence of an ignition source. Burning point typically refers to the temperature at which a substance will continue to burn once it is ignited, rather than the spontaneous ignition ability. These distinctions are important for understanding combustion and fire prevention strategies in firefighting.