Is incombustible and noncombustible the same thing?

While incombustible and noncombustible are often used interchangeably, they are not exactly the same thing.

Here's the breakdown:

* Incombustible: This refers to materials that cannot burn under any circumstances. They do not release flammable vapors and cannot sustain combustion. Examples include:

* Some metals like steel

* Stone

* Glass

* Certain ceramics

* Noncombustible: This term is broader and encompasses materials that do not easily ignite and burn. They may be resistant to burning but can still be damaged or decompose under high heat. Examples include:

* Wood treated with fire retardants

* Some plastics

* Certain fabrics

Key Difference:

The main difference lies in the level of resistance to fire. Incombustible materials are completely impervious to burning, while noncombustible materials can still be affected by fire, though they might not readily ignite.

In practice:

In many contexts, these terms are used interchangeably because the distinction might not be crucial. However, in specific applications, such as building codes and fire safety regulations, the difference can be significant.

In conclusion:

While incombustible is a stronger and more absolute term, noncombustible is a broader term that describes materials with some resistance to burning.