Controlled rheology polypropylene (CR-PP): High meltflow index polypropylene grades are produced by post reactor treatment. These high melt-flows are achieved by peroxide-initiated degradation during extrusion of the polypropylene. The advantage of this process is the high flexibility; the peroxide concentration controls the final viscosity. Coagent for flame retardant polystyrene: Polystyrene is made flame retardant by the use of halogen-containing additives such as hexabromocyclododecane (HBCD). Perkadox® 14S-FL can be used as a synergist in such systems thereby leading to a significant reduction in the amount of HBCD required.