Cellulose

In the United States cellulose insulation must meet the strict flammability standards of the Consumer Products Safety Commission. Fire retardants are applied during the manufacturing process to insure fire safety. Cellulose insulation products routinely qualify for Class A flame spread ratings. Cellulose insulation has been tested and qualified as a fire stop around steel through penetrations and as a fire block in wood frame walls. In several demonstration burns, buildings with cellulose have retained structural integrity significantly longer than buildings with other fiber materials. In one demonstration the ceiling of a fiberglass insulated building collapsed 22 minutes after fires were ignited. A ceiling with cellulose insulation stayed in place for 70 minutes -- an important margin of safety for building occupants and fire fighters. The National Research Council Canada added scientific support to the burn demonstrations with a study that concluded fiber glass reduced the fire resistance of insulated assemblies while cellulose improved fire resistance 22% to 55%. NRCC tested a cellulose insulated floor/ceiling assembly in 1995 and found it to have approximately 50% higher fire resistance than a fiberglass insulated assembly. The cellulose assembly resisted direct fire exposure about 30 minutes longer than the fiber glass test assembly. A cellulose-insulated wall tested in 1999 by Omega Point Laboratories was found to be 46% to 77% more fire resistant than an uninsulated wall. As a result of this fire resistance, under some data based on computer modeling that showed cellulose insulation in a wall resulted in lower moisture levels in other wall components than in an uninsulated wall. As a result of this fire resistance, under some fire conditions, cellulose gives building occupants more time to reach safety and fire fighters more time to save the structure.