Ship breaking or ship demolition is a type of ship disposal involving the breaking up of ships for either a source of parts, which can be sold for re-use, or for the extraction of raw materials, chiefly scrap. It may also be known as ship dismantling, ship cracking, ship recycling, or ship disposal. Modern ships have a lifespan of 25 to 30 years before corrosion, metal fatigue and a lack of parts render them uneconomical to run. Ship breaking allows the materials from the ship, especially steel, to be recycled and made into new products. This lowers the demand for mined iron ore and reduces energy use in the steel-making process. Equipment on board the vessel can also be reused. While ship breaking is, in theory, sustainable, there are concerns about the use of poorer countries without stringent environmental legislation. It is also considered one of the world's most dangerous industries and very labour-intensive.