Every second counts once a fire has started.

With fires developing five to 10 times faster today than in the 1950s, the safety of building occupants and first-responders depends overwhelmingly on how the building performs during a fire. Importantly, this includes the release of thick toxic smoke, which kills more people than the fire does¹.

Our stone wool products will not develop toxic smoke. The core material is non-combustible. It does not contribute to the development and spread of fire, even when directly exposed to flames.

Given stone wool’s volcanic origins, it can withstand extreme temperatures up to 2150 degrees Fahrenheit (1177 Celsius). All of these beneficial qualities of stonewool contribute to adding the critical moments needed to find safety in the event of a fire.

Class A Fire Rating Ceiling Tile

Many commercial applications require a Flame Spread Index of 25 or less and a Smoke Developed Index of 50 or less. Products that fulfill these requirements are labeled with a Fire Hazard Classification 25/50 (FHC 25/50) or a “Class A” rating. The Class A rating is designated for products per ASTM E1264 “Standard Classification for Acoustical Ceiling Products.”

We rigorously test our fire-rated products to ensure they meet or exceed code requirements.

Demonstrating fire resistance, acoustic ceiling panels and tiles are required to be tested for surface burning characteristics. The North American standard is Underwriters Laboratories (UL) 723/ASTM E84, “Standard Test Method for Surface Burning Characteristics of Building Materials.”

Testing requires 24 feet of material to be exposed to a flame ignition source in a Steiner Tunnel Test to determine how far the fire will spread during 10 minutes, and how much smoke is developed during this period.

The test was developed by Al Steiner of UL and has been incorporated as a reference into North American standards for materials testing. The progress of the flame front across the test material is measured by visual observation, while the smoke emitted is measured as a factor of optical density.

A Flame Spread Index and a Smoke Developed Index are calculated from these results. Both use an arbitrary scale base on an asbestos-cement board having a value of 0, and red oak wood having a value of 100. Our stone wool ceiling products can be specified to meet the most stringent requirements with a maximum Flame Spread Index of 0 and a maximum Smoke Developed Index of 5.

Sources

_{UL, Analysis of Changing Residential Fire Dynamics and Its Implications on Firefighter Operational Timeframes, https://newscience.ul.com/wp-content/uploads/2014/04/Analysis_of_Changing_Residential_Fire_Dynamics_and_Its_Implications_on_Firefighter_Operational_Timeframes.pdf}