Recovery and reprocessing of waste materials for use in new products. The basic phasis in recycling are the collection of waste materials, their processing or manufacture inti new products, and the purchase of new products, which may then themselves be recycled. Typical material that are recyled include iron and steel scrap, aluminium cans, glass bottles, paper, wood and plastics. The materials resused in recycling serve as substitutes for raw materials obtained from such increasingly scarce natural resources as petroleum natural gas, coal, mineral ores, and trees. Recycling can help reduce the quantities of solid waste deposited in Landfills, which have become increasingly expensive. Recycling also reduces the pollution of air, water and land resulting from waste disposal.