What does "flammable" indicate regarding a material?

The term "flammable" specifically refers to a material's ability to ignite easily and combust under normal conditions. A flammable substance is one that can catch fire and sustain a flame when exposed to a spark, flame, or heat source at relatively low temperatures. This characteristic is essential in safety protocols, especially in environments where chemical substances are present, as flammable materials pose a significant risk of fire hazards.

In contrast, the other options describe different properties. A material that requires high temperatures to ignite would not be classified as flammable, as it takes more energy to initiate combustion. A substance that emits toxic vapors when heated may be dangerous, but this property does not pertain directly to flammability. Lastly, describing a material as stable and non-reactive speaks to its chemical stability and lack of reactivity, which is the opposite of what is indicated by "flammable." Thus, understanding the implications of "flammable" is crucial for safety in any setting involving potentially dangerous materials.