Abstract: A description is given of continuous fibers based on cellulose and/or cellulose derivatives, more particularly for producing flame-retardant textiles or carbon fibers. The cellulose and/or the cellulose derivatives are in a dehydrated form in the continuous fibers. The oxygen content is 29 to 39 wt %, the limiting oxygen index LOI is 25 to 40 (according to DIN EN ISO 6941; 2004-05) and the density is 1.3 to 1.45 g/cm3 (according to DIN 65569-1; 1992-10). The continuous fibers may be produced advantageously by impregnating the starting fibers with a solution, more particularly an aqueous solution, of a specific salt which under thermal conditions releases a dehydrating acid which brings about the dehydration of cellulose and/or of cellulose derivatives in a subsequent thermal stage. The continuous fibers of the invention can be used in particular to produce advantageous carbon fibers.