Abstract: Plastic compositions containing a three component system consisting of (1) a polysulfone, (2) certain bis-phenoxy compounds having the formula: ##STR1## WHEREIN Z is bromine, m and m' are each integers having a value of 1-5 with the proviso that the total bromine atom content is from 6 to 10, and "T" is a straight or branched chain carbon group having 1 to 4 carbon atoms, and (3) an enhancing agent, hereinafter defined.