2. Re-use . The collection and re-use of material,for example, the re-use of glass bottles,involves the collection , cleaning and re-use of the same glass bottles. Tyre re-treading would also come into this category , where many truck tyres may be re-treaded many times throughout their lifetime. Re-use may also include new uses for the item once they have served their original purpose. For example, the use of used tyres for boat fenders and as silage covers. Re-use can be commercially attractive in some circumstances. However, re–use may not be desirable in all cases since the environmental and economic cost of re-use in terms of energy use,cleaning , recovery,transportation etc., may outweigh its benefits.