Flame retardants for polymer compositions which are mixtures including triaryl phosphate esters represented by the following formula: where R1-R15 can independently be located in the ortho, meta or para positions on their respective phenol rings and are, independently, H or branched or linear alkyl groups having 3 to 11 carbon atoms and the mole ratio of the alkylate to phenol in the mixtures is at least about 0.77, preferably greater than about 0.81, and most preferably greater than about 0.85. The higher alkylated mixtures of triaryl phosphate esters can be incorporated into polymer compositions alone or in combination with other flame retardants.