: 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

There are multiple definitions. Sometimes it makes a lot of sense to even categorize them based on their flamability. In general something is considered flammable if it releases energy when you expose it to hot air. For example NFPA 704 scores materials as a 0 on flamability if it does not catch fire in air when exposed to 820 °C for five minutes. However other classifications and standards have different thresholds.