Abstract: The invention relates to a non-inflammable fiber product that can be used as flame-resistant material or insulating material or both. The invention seeks to provide a material made of used cellulose or cellulose-containing refuse, which had not been sensibly used hitherto. The new fiber product consists of 30 to 97 wt. % cellulose-containing fiber or a cellulose-containing fiber mixture; 0.01 to 1 wt. % nonionic surface active agent; 1 to 5 wt. % aluminum oxide finely distributed on and in the fibers, and 0 to 68 wt. % filling material, as well as optionally one or more additional biocides. Said product can be processed in bulk or as pressed plate.