Polyurethane foams containing brominated diphenyl ether

In the method of making a flexible or semiflexible low density polyetherurethane foam using the one-shot or prepolymer process by the reaction of (A) a polyetherpolyol having from two to four hydroxyl groups and having a molecular weight of from about 1,000 to 10,000, (B) an organic polyisocyanate and (C) a blowing agent comprising water in admixture with (D) a surfactant, (E) a catalyst, (F) finely divided zinc oxide in an amount of from about 0.1 to 10 parts by weight per 100 parts by weight of said polyol, and (G) finely divided antimony trioxide in an amount of from about 0.5 to 15 parts by weight per 100 parts by weight of said polyol, the improvement comprising incorporating in the formulation prior to foaming a brominated diphenyl ether having from 4 to 10 bromine atoms in an amount of from about 5 to 25 parts by weight per 100 parts by weight of said polyol.