What is the minimum temperature at which a substance ignites called?

The minimum temperature at which a substance ignites is referred to as the ignition temperature. This term specifically denotes the point at which a material will spontaneously ignite without an external ignition source. Understanding ignition temperature is crucial in fire safety and firefighting operations, as it helps determine the conditions under which materials can become fire hazards.

The other terms may seem related but have distinct meanings. The kindling point often refers to a similar concept but can imply a lower temperature at which a substance can easily be ignited by a small flame. The combustion threshold isn't a commonly used term in fire science for ignition but typically relates to the specific conditions required to sustain combustion rather than the initial igniting temperature. Lastly, the flash point is the lowest temperature at which vapor from a combustible liquid can ignite when exposed to an open flame, but it does not represent the substance itself igniting spontaneously. Understanding these differences helps in effectively assessing fire risks and managing firefighting tactics.