As a part of an innovation project, BASF has created a half-liter polystyrene bottle weighing a mere 7.5 grams - the world's lightest half-liter PS bottle ever - employing a conventional stretch blow-molding machine, the company said in a statement. The innovation project, BASF says, gave an opportunity to see how extremely lightweight bottles for dairy products can be made of polystyrene using stretch blow-molding methods. Accordingly, the low weight cuts costs and uses less resources. According to the company, PS has a lower density than PET and thus can be used to produce bottles that weigh less while having the same wall thickness. Due to this, BASF recommends the new polystyrene type (PS BX 3580) specifically for containers used for milk products.