: How do you define something as flammable? Which criteria of an object is used as reference?

Question

: How do you define something as flammable? Which criteria of an object is used as reference?

In: Physics

Answer 1

An objects (usually a liquids though) Flashpoint is used. Which is the minimum temperature necessary to cause an item to catch fire.

For liquid this is ~100°F.

For solids its any solid that is readily combustible or can cause combustion through friction. Lithium for batteries comes to mind, which will readily combust/react when exposed to the air.

Edit: I’ve used transportation standards as a reference, different samtandards classify flammability differently depending on the nature of the work being done. 100°F would make for a class 3 flammable liquid i believe.