A method for making fire retardant material including fire retardant cellulosic insulation is described. The method includes an arrangement for adding one or more feedstocks and a fire retardancy chemical compound to a common blend tank prior to feedstock drying. The one or more feedstocks may include at least one virgin pulp stock feed and at least one recycled material stock feed. The amount and type of both the virgin feedstock and the recycled material feedstock is selectable. Old newsprint (ONP) may be one type of recycled material feedstock. Another suitable type of recycled material feedstock is old corrugated containers (OCC). The method further includes retaining the fiber feedstock and the chemical compound together for enough time to ensure adherence or impregnations of enough of the chemical to the fibers after the drying process. Fluffing or fiberizing of the treated fibers may be accomplished under less severe conditions than ordinarily employed when making conventional cellulose insulation.