Which of the following materials is NOT typically considered combustible?

Steel is not typically considered combustible because it has a high melting point and does not ignite or burn in the way that organic materials do. Combustible materials are those that can catch fire and burn easily, which includes items like wood, plastic, and textiles. These materials have organic compositions that allow them to support combustion under the right conditions.

In contrast, steel is a metal that can withstand high temperatures without readily igniting. While it can be involved in fires—for instance, when exposed to extreme heat that causes it to weaken or deform—it does not contribute to the fire itself as a combustible material would. Thus, identifying steel as non-combustible is crucial in fire safety and inspection practices since it helps in assessing risks and determining safety protocols in buildings and construction.