Comfort-Zone gives you the highest R Value per inch, higher than fiberglass or rockwool. Comfort-Zone's high density helps suppress air infiltration by completely filling in around wood framing members, plumbing, electrical wiring and other obstacles. Giving you a much tighter seal. Comfort-Zone is a safe product for you and your family. Because of its permanent fire retardant treatment, Comfort-Zone has been shown to slow the spread of fire. Plus, because Comfort-Zone is made from natural non-carcinogenic wood fibers, there are none of the health concerns associated with fiber glass and rockwool.