Flame retardant polyolefin composition for shipping pallets

A flame retarded polyolefin composition comprising a thermoplastic polyolefin polymer, an inorganic flame retardant and a synergist comprising a metal phosphonate represented by the general formula (I):

• where Me is a metal, n is equal to the valency of the metal and is in the range of from 1 to 4, R1 is a linear or branched alkyl of up to about 12 carbon atoms, R2 is a linear or branched alkyl of up to about 12 carbon atoms, or a substituted aryl or an unsubstituted aryl of the general formula (II):
• where R3 is hydrogen, or a branched or linear alkyl of up to about 4 carbon atoms, or NH2 or CN or NO2, wherein the inorganic flame retardant is present in an amount of from about 5 weight percent to about 40 weight percent.