Flame Seal Class-A Coating™ (FS-A) is latex based, single component class-A coating designed for use as a fire retardant coating over combustible interior materials. The product can be applied to most substrates including, wood, plywood, OSB, gypsum wallboard. FS-A can also be used on metal surfaces with the use of a primer. Please check certification and manufacturer information for details. When properly applied, FS-A meets ASTM E-84 class-A testing requirements for flame and smoke spread. When FS-A is exposed to fire or extreme heat, a protective layer of Carbon Foam develops and prevents the fire and heat from transferring to the Substrate. This coating comes in standard in dark gray, white can be requested but may require a lead time.