Thermafiber® FireSpan® products are designed to provide enhanced fire protection in curtain wall and perimeter fire containment systems. These products are non-combustible, moisture-resistant, non-corrosive, non-deteriorating, mildew resistant and vermin-resistant. Its natural dark color provides shadowing in glass spandrels. FireSpan® 40 & 90 insulations provide thermal insulation, fire containment, enhanced acoustical performance, and vapor control in many different UL and Intertek (formerly OPL) listed fire containment assemblies of 1, 2, and 3-hr ratings.