What is the primary purpose of a fire separation?

The primary purpose of a fire separation is to act as a horizontal or vertical fire resistance-rated assembly designed to restrict the spread of fire. Fire separations are crucial in building design because they create barriers that limit the movement of smoke and flames between different areas of a structure during a fire incident. This containment helps ensure that fires remain localized, allowing occupants more time to evacuate and reducing the overall risk to life and property.

The other options do not encompass the main function of fire separations. While preventing hazardous materials from igniting or containing flammable gases is important, it does not specifically reflect the role of a fire separation. Likewise, while fire retardant materials are beneficial in construction, they serve a different purpose than the structural integrity provided by fire separations. Thus, understanding that fire separations are specifically designed to restrict fire spread confirms the accuracy of the correct answer.