Which characteristic is NOT part of noncombustible materials?

Noncombustible materials are defined by their ability to withstand fire without significant degradation or flammability. These materials do not ignite easily, making them suitable for applications where fire safety is paramount.

Heat resistance is an essential characteristic since noncombustible materials can endure high temperatures without catching fire. Similarly, being fire resistant aligns with their definition, as these materials are specifically designed to resist the spread of flames and maintain structural integrity during a fire. Low flammability is also a key feature, indicating that noncombustible materials have a very limited capacity to catch fire.

The characteristic that is not part of noncombustible materials is being ignition prone. This term describes materials that are likely to catch fire when exposed to an ignition source, which directly contradicts the definition of noncombustibility. In summary, noncombustible materials should not be associated with a high likelihood of igniting.