A flexible polyurethane foam comprising a flame retardant blend comprising: a mono-hydroxyl-functional dialkyl phosphinate compound of the formula (I-A): wherein: R 1 and R 2 are selected from a linear or branched alkyl group containing from 1 to 4 carbon atoms; and, X is either or and when X is Z is -(Y-O) n -, wherein Y is a linear or branched alkylene group containing from 2 to 8 carbon atoms and n represents an integer from 1 to 20; k may be 0 or 1; R 3 is selected from hydrogen, a mono-hydroxy-terminated linear or branched alkylene group containing from 2 to about 8 carbon atoms; and, provided that when k is zero, R 3 is the mono-hydroxy-terminated linear or branched alkylene group and when k is 1, R 3 is hydrogen, and when X is R 4 and R 5 are each independently selected from H, a linear or branched alkyl group containing from 1 to 8 carbon atoms, a linear or branched alkenyl group containing from 2 to 8 carbon atoms, a halo-substituted alkyl group containing from 1 to 8 carbon atoms, an alkoxy group containing from 1 to 8 carbon atoms, an aryl group containing from 6 to 12 carbon atoms and an alkylaryl group containing from 7 to 16 carbon atoms, or R 4 and R 5 are bonded to each other to form a cycloalkyl group containing from 5 to about 8 carbon atoms; and, a phosphate compound, wherein the flame retardant blend contains 25 to 95% by weight of phosphate, based on the total weight of the flame retardant blend. a mono-hydroxyl-functional dialkyl phosphinate compound of the formula (I-A): wherein: R 1 and R 2 are selected from a linear or branched alkyl group containing from 1 to 4 carbon atoms; and, X is either or and when X is Z is -(Y-O) n -, wherein Y is a linear or branched alkylene group containing from 2 to 8 carbon atoms and n represents an integer from 1 to 20; k may be 0 or 1; R 3 is selected from hydrogen, a mono-hydroxy-terminated linear or branched alkylene group containing from 2 to about 8 carbon atoms; and, provided that when k is zero, R 3 is the mono-hydroxy-terminated linear or branched alkylene group and when k is 1, R 3 is hydrogen, and when X is R 4 and R 5 are each independently selected from H, a linear or branched alkyl group containing from 1 to 8 carbon atoms, a linear or branched alkenyl group containing from 2 to 8 carbon atoms, a halo-substituted alkyl group containing from 1 to 8 carbon atoms, an alkoxy group containing from 1 to 8 carbon atoms, an aryl group containing from 6 to 12 carbon atoms and an alkylaryl group containing from 7 to 16 carbon atoms, or R 4 and R 5 are bonded to each other to form a cycloalkyl group containing from 5 to about 8 carbon atoms; and, R 1 and R 2 are selected from a linear or branched alkyl group containing from 1 to 4 carbon atoms; and, X is either or and when X is Z is -(Y-O) n -, wherein Y is a linear or branched alkylene group containing from 2 to 8 carbon atoms and n represents an integer from 1 to 20; k may be 0 or 1; R 3 is selected from hydrogen, a mono-hydroxy-terminated linear or branched alkylene group containing from 2 to about 8 carbon atoms; and, provided that when k is zero, R 3 is the mono-hydroxy-terminated linear or branched alkylene group and when k is 1, R 3 is hydrogen, and when X is R 4 and R 5 are each independently selected from H, a linear or branched alkyl group containing from 1 to 8 carbon atoms, a linear or branched alkenyl group containing from 2 to 8 carbon atoms, a halo-substituted alkyl group containing from 1 to 8 carbon atoms, an alkoxy group containing from 1 to 8 carbon atoms, an aryl group containing from 6 to 12 carbon atoms and an alkylaryl group containing from 7 to 16 carbon atoms, or R 4 and R 5 are bonded to each other to form a cycloalkyl group containing from 5 to about 8 carbon atoms; and, a phosphate compound, wherein the flame retardant blend contains 25 to 95% by weight of phosphate, based on the total weight of the flame retardant blend. <EOS>