Today, a small proportion of plastic waste is recycled as plastic in developed countries, but a very large proportion - mainly that which cannot be recycled - ends up in landfills. But they could be recycled by breaking them down into their raw materials. In the USA, for example, plastics could be pyrolysed to produce diesel oil. A relatively large proportion of PET is recycled back into production, but not all used PET is made into regranulate suitable for food packaging. A Canadian inventor is able to make an excellent food-grade polymer from PET waste fished from the oceans by repolymerising it after depolymerisation.