Thermafiber. Thermafiber mineral wool insulation is made with up to 90% post-industrial recycled content. It exceeds the California purchase specifications for total volatile organic compounds and general emissions with formaldehyde concentrations of 12 ppb, exceeding the California standard of 20 ppb maximum for formaldehyde concentration. Thermafiber can provide high sound-transmission coefficients that improve indoor environmental quality. The product also offers fire resistance of more than 2,000 degrees F for more than five hours, the maker says. 888.834.2371.