Abstract: Disclosed is a fire retardant composition including at least one boron containing compound selected from disodium octaborate tetrahydrate, Colemanite, Ulexite, calcium borate, metaboric acid and boron oxide, and at least one further boron containing compound selected from anhydrous borax, borax pentahydrate, borax decahydrate, disodium octaborate tetrahydrate, Colemanite, Ulexite, calcium borate, metaboric acid, and boron oxide. Also disclosed is the use of a composition including only one boron containing compound, selected from anhydrous borax, borax pentahydrate, borax decahydrate, disodium octaborate tetrahydrate, Colemanite, Ulexite, calcium borate, metaboric acid, boron oxide and boric acid, as a fire retardant agent or heat transfer reducing agent. Further disclosed is a method of increasing fire resistance of a material or reducing heat transfer in a material, and a material of improved fire resistance and reduced heat transfer.

Abstract: A method of increasing fire resistance of a synthetic material by bringing the material into contact with a fire retardant composition including boric acid and a salt of boric acid, the fire retardant composition being free from carboxymethylcellulose. A synthetic material of increased fire resistance. A fire retardant composition and a method for preparing a fire retardant composition.