Abstract: A dehydrated mixture of hydrated sodium antimonate and ionomer polymer flame retard a polymer or resin composition such as film, fiber, electrical connection and molded part. From 10 to 90 parts sodium antimonate containing 3% moisture mixed with 10 to 90 parts ionomer polymer or polyethylene or ethylene vinyl acetate are added to a single screw vented extruder to produce pellet concentrate with a 0.1% moisture content for flame proofing PET. A composition may be prepared in a single or twin screw extruder or in a high shear blender in the presence of glass fiber by adding a dehydrated mixture of an alkyl tertabromophtalate and sodium antimonate and brominated polystyrene to polyethylene terephthalate or polybutylene terephthalate. A preferred temperature range for dehydration of hydrated sodium antimonate in the presence of a polymer is between 150° C. and 250° C.