Abstract: Fire retarding and smoke inhibiting aqueous composition and a method for a one-step impregnation of aqueous-absorbable--and normally inflammable materials, such as wood, paper and textiles, said composition comprising ammoniumphosphates, phosphoric acid, water soluble metal salts with ability to form water insoluble salts with phosphate ions and/or ammoniumphosphate ions, and other optional additives.The composition comprises in combination:0.5-90% by weight monoammoniumphosphate and/or diammoniumphosphate,0.1-30% water-soluble metal salts with ability to form water insoluble salts with phosphate ions and/or ammoniumphosphate ions,1-20% by weight acid especially phosphoric acid (85%),1-15 % by weight dicyandiamide, andoptionally up to 5% by weight additivesin a total concentration of from 1 to 50% by weight with respect to the total weight of the aqueous solution, whereby phosphoric acid and dicyandiamide are present in the form of the reaction product guanylureaphosphate.

Abstract: Flame retarding and smoke retarding aqueous solutions consisting essentially of: 70-96 weight % of a mixture of ammonium phosphate and ammonium sulphate, 1-20 weight % NaHCO.sub.3, 1-10 weight % EDTA, and water in an amount resulting in an aqueous solution comprising 11-45 weight % solids on the basis of the total weight of the aqueous solution. Methods of producing and using the flame retarding and smoke retarding aqueous solutions to impregnate absorbent porous materials, such as wood, rayon, cotton, wool and similar textile materials are also taught.