Polystyrene is one of the important commercial polymers, widely used in various industrial fields. One of the important uses of PS is in the manufacture of cover signals lamp of some automobiles. PS is subjected to the irradiation of sunlight on outdoor exposure.Almost all synthetic polymers require stabilization against adverse environmental effects. It is necessary to find a means to reduce or prevent damage induced by environmental components such as heat, light or oxygen. This can be achieved through addition of special chemicals, light or UV stabilizers, that are selected to be compatible with the resin and the specific application considered. The photostabilization of polymers may be achieved in many ways. The following stabilizing systems have been developed, which depend on the action of stabilizer. a) Light screeners. b) U.V. absorbers, c) Excited state quenchers, d) Peroxide decomposers and e) Free radical scavengers, of these it is generally believed that types c), d) and...