What defines ignition-resistant building materials?

The definition of ignition-resistant building materials is centered around their ability to withstand the initial stages of a fire without igniting or rapidly burning. These materials are specifically engineered or treated to minimize the risk of combustion when exposed to flames or high temperatures. The focus is on enhancing fire safety by using substances that can delay ignition, thereby giving inhabitants more time to respond to a fire emergency and reducing the overall increase in fire intensity.

In contrast, the other options do not align with the characteristics of ignition-resistant building materials. Materials that easily catch fire do not possess the qualities necessary for safety and protection from wildfires. Cost and accessibility do not inherently define the fire-resistance of materials; instead, they may pertain to economic factors rather than safety standards. Lastly, a lifespan of less than five years does not indicate anything about fire resistance, as durability and fire safety are separate concerns.