Flame retardant and/or self-extinguishing urethane polymer compositions or shaped articles made therefrom are characterized in that the flame-retardant properties are due to the presence of (1) combinations comprising effective amounts of ammonium bromide and of either (a) antimony oxide, arsenic oxide, phosphorus oxide, the nitrogen-phosphorus complex resulting from the reaction of ammonia with phosphorus pentoxide, or an antimony salt, or of (b) a mixture of two or more of such antimony, arsenic and phosphorus compounds; (ii) a combination comprising effective amounts of a polybromoalkyl phosphate, containing at least 45% by weight of bromide, and of either (a) antimony oxide, arsenic oxide, phosphorus oxide, the nitrogen-phosphorus complex resulting from reaction of ammonia with phosphorus pentoxide, or an antimony salt, or of (b) a mixture of two or more such inorganic antimony, arsenic and phosphorus compounds; (iii) a combination comprising effective amounts of a phosphorus oxide and at least one organic flame-proofing agent containing at least 45% by weight of bromine and having a plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule; (iv) a combination comprising effective amounts of the nitrogen-phosphorus complex resulting from the reaction of ammonia with phosphorus pentoxide and at least one organic flame-proofing agent other than a polybromoalkyl phosphate, which organic flame-proofing agent contains at least 45% by weight of bromine and has a plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule; or (v) a combination comprising effective amounts of a halogen-containing antimony salt and at least one organic flame-proofing agent other than a polybromoalkyl phosphate, which organic flame-proofing agent contains at least 45% by weight of bromine and has a plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule. The combination of the different kinds of compound imports greater self-extinguishing properties than does the same amount of either of the materials used alone. Specified bromides are methyl 2,3-dibromopropionate, tris(2,3-dibromopropyl) phosphate, carbon tetrabromide, tetrabromoethylene, 1,2-dibromo-1,1,2,2-tetrachloroethane, 1,1,2,2-tetrabromoethane, dibromodichloromethane, pentabromoethane, hexabromoethane, dibromosuccinic acid, 1,2-di(dibromomethyl) benzene, a ,b -dibromoethyl benzene, 1,2,3,4,5,6-hexabromocyclohexane, 1,2,3,4,5-pentabromo-6-chlorocyclohexane, tetrabromodichloro-cyclohexanes and tribromotrichlorocyclohexanes. The specified inorganic compounds include antimonous oxide, arsenous oxide, arsenic oxide, phosphoric oxide, antimonous chloride, bromide or iodide, antimony oxychloride or antimonous sulphide. The phosphoric oxide is preferably used as a nitrogen-phosphorus complex obtained by heating phosphorus pentoxide with excess anhydrous ammonia. The polymer compositions can be used as mouldings, castings, coatings, laminates and foams and in potting electrical equipment. In Example (1) a composition of a polyol (obtained by reacting glycerol and sucrose with propylene oxide), triethylene diamine, dibutyltin dilaurate and a copolymer of polyethylene glycol and dimethylsiloxane, is mixed with trichlorofluoromethane and an adduct of toluene-2,4 and 2,6-diisocyanates with a propylene oxide/glycerol condensate. Tris(2,3-dibromopropyl) phosphate and finely divided antimonous oxide are stirred in, the mixture is poured into a mould, and the gelled foam is cured at 70 DEG C. The use of other flame-proofing materials is illustrated in further examples of the preparation of foams. Other starting materials used include (22 to 24) octakis (2-hydroxypropyl) sucrose, and an adduct of toluene diisocyanates with a propylene oxide/2,2-di(hydroxymethyl) butanol condensate; (25) a polyester from glycerine, adipic acid and phthalic anhydride, and tolylene diisocyanate, foam being obtained by adding dioctyl sulphosuccinate in acetone and zinc distearate; (30) a mixture of propoxylated glycerol and polypropylene oxide; (44) a tolylene diisocyanate/polyol reaction product and octakis[2-(2-hydroxypropoxy) propyl]-sucrose. Specification 793,501 is referred to.ALSO:Flame retardant and/or self-extinguishing urethane polymer compositions or shaped articles made therefrom are characterised in that the flame-retardant properties are due to the presence of (i) combinations comprising effective amounts of ammonium bromide and of either (a) antimony oxide, arsenic oxide, phosphorus oxide, the nitrogen-phosphorus complex resulting from the reaction of ammonia with phosphorus pentoxide, or an antimony salt or of (b) a mixture of two or more of such antimony, arsenic and phosphorus compounds; (ii) a combination comprising effective amounts of a polybromoalkyl phosphate, containing at least 45% by weight of bromine and of either (a) antimony oxide, arsenic oxide, phosphorus oxide, the nitrogen-phosphorus complex resulting from reaction of ammonia with phosphorus pentoxide, or an antimony salt, or of (b) a mixture of two or more such inorganic antimony, arsenic and phosphorus compounds; (iii) a combination comprising effective amounts of a phosphorus oxide and at least one organic flame-proofing agent containing at least 45% by weight of bromine and having a plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule; (iv) a combination comprising effective amounts of the nitrogen-phosphorus complex resulting from the reaction of ammonia with phosphorus pentoxide and at least one organic flame-proofing agent other than a polybromoalkyl phosphate, which organic flame-proofing agent contains at least 45% by weight of bromine and has a plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule; or (v) a combination comprising effective amounts of a halogen-containing antimony salt and at least one organic flame-proofing agent other than a polybromoalkyl phosphate, which organic flame-proofing agent contains at least 45% by weight of bromine and has plurality of bromine atoms in an aliphatic or cycloaliphatic portion of the molecule. The combination of the different kinds of compound imparts greater self-extinguishing properties than does the same amount of either of the materials used alone. Specified bromides are methyl 2, 3-dibromopropionate, tris(2, 3-dibromopropyl) phosphate, carbon tetrabromide, tetrabromo-ethylene, 1, 2-dibromo1, 1, 2, 2-tetrachloroethane, 1, 1, 2, 2-tetrabromoethane, dibromodichloromethane, pentabromoethane, hexabromoethane, dibromo-succinic acid, 1, 2-di (dibromomethyl) benzene, a , b -dibromoethyl benzene, 1, 2, 3, 4, 5,-pentabromo-6-chlorocyclohexane, tetrabromodichloro-cyclohexanes and tribromotrichlorocyclohexanes. The specified inorganic compounds include antimonous oxide, arsenous oxide, arsenic oxide, phosphoric oxide, antimonous chloride, bromide or iodide, antimony oxychloride or antimonous sulphide. The phosphorus oxide is preferably used as a nitrogen-phosphorus complex obtained by heating phosphorus pentoxide with excess anhydrous ammonia. The polymer compositions can be used as mouldings, castings, coatings, laminates and foams and in potting electrical equipment. In Example (1) a composition of a polyol (obtained by reacting glycerol and sucrose with propylene oxide), triethylenediamine, dibutyltin dilaurate and a copolymer of polyethylene glycol and dimethylsiloxane is mixed with trichlorofluoromethane and an adduct of toluene -2, 4 and 2, 6-diisocyanates with a propylene oxide/glycerol condensate. Tris (2, 3-dibromopropyl)- phosphate and finely divided antimonous oxide are stirred in, the mixture is poured into a mould, and the gelled foam is cured at 70 DEG C. The use of other flame-proofing materials is illustrated in further examples of the preparation of foams. Other starting materials used include (22 to 24) octakis (2-hydroxypropyl)-sucrose, an adduct of toluene diisocyanates with a propylene oxide/2, 2-di(hydroxymethyl) butanol condensate; (25) a polyester from glycerine, adipic acid and phthalic anhydride, and tolylene diisocyanate, foam being obtained by adding dioctyl sulphosuccinate in acetone and zinc distearate; (30) a mixture of propoxylated glycerol and polypropylene oxide; (44) a tolylene diisocyanate/polyol reaction product and octakis [2-(2-hydroxypropoxy) propyl]- sucrose. Specification 793,501 is referred to.