Plastics have become ubiquitous because they are such a versatile material. They are
easily formed into about any shape, and there are many types and grades of plastics with very different properties, which can be easily tailored to meet a wide variety of specific end use requirements.
Furthermore, unlike steel or wood, plastics usually do not have to be painted or coated to change
their color or protect them from the elements. Their low density offers important light-weighting
benefits in a wide variety of products. Most plastics are derived from petrochemicals and natural
gas. Ever more remote locations and drilling ever deeper wells are needed to extract these limited resources. These practices have significant economic and environmental implications that are already
evident today. The recycling of plastics can save as much as 90% of the energy of making plastics
using traditional chemical synthesis and polymerization routes and can save between 1 and 4 tons of
CO
2 per ton of virgin plastics replaced. But recycling plastics is more complicated and difficult compared to recycling metals, posing both technical and economic challenges. After decades of research
and mostly small-scale commercial undertakings, solutions to these difficult challenges have begun
to emerge in several locations around the world and demonstrate how societies can finally realize the
consequent environmental and economic benefits of recovering this valuable resource and keeping it from polluting our environment.