The number of companies handling and reclaiming post-consumer plastics today is nearly six times greater than in 1986, growing from 310 companies to 1,792 in 1998. The number of end uses for recycled plastics continues to grow. The federal and state government as well as many major corporations now support market growth through purchasing preference policies. Early in the 1990s, concern over the perceived reduction of landfill capacity spurred efforts by legislators to mandate the use of recycled materials. Mandates, as a means of expanding markets, can be troubling.
Mandates often fail to take health, safety and performance attributes into account.
Moreover, they are unable to acknowledge the life cycle benefits to the environment, such as the efficient use of energy and natural resources. Feedstock Recycling Pyrolysis involves heating plastics in the absence or near absence of oxygen to break down the long polymer chains into small molecules. Under mild conditions polyolefins can yield a petroleum-like oil. Special conditions can yield monomers such as ethylene and propylene. Chemical recycling is a special case where condensation polymers such as PET or nylon are chemically reacted to form starting materials.