For class A interior finish materials, what is the flame spread index range?

The flame spread index for Class A interior finish materials is indeed between 0 and 25. This classification is crucial for assessing the fire performance of materials used in construction, particularly when it involves safety in the event of a fire. A flame spread index within this range indicates that the material exhibits the highest level of fire resistance and low flame spread, which is essential for interior finishes in occupancies where life safety is a primary concern.

Materials with a flame spread index of 0 to 25 are considered to be effective in delaying the onset of fire spread, providing more time for occupants to evacuate and for firefighting efforts to be initiated. This makes them suitable for use in various types of buildings, especially those that require a higher degree of fire safety due to occupancy type or building size.

In contrast, materials with higher flame spread indices would indicate a greater potential for rapid fire spread, which would not meet the stringent requirements set for Class A materials. Thus, the classification system plays a critical role in ensuring construction products contribute to the overall safety of a building.