Since the mid-1950s, when commercial plastics production began in earnest, over 8 billion metric tons of primary plastics have been produced, principally from hydrocarbon feedstock. Almost one-third of these plastics remain in use, mostly in infrastructure, buildings, transportation vehicles and industrial machinery. Only 500 million tons or about 6% of the produced plastics have been recycled; the majority has been discarded (55%) or incinerated (8%).
About 2% of that plastic waste, or 8 million tons – predominantly from China, Indonesia, Philippines, Sri Lanka and Vietnam – ends up in the oceans and other marine ecosystems each year. It gets there in a variety of ways, in both visible and microscopic form, through accidental spills, airborne and water borne microplastics and microfibers, careless dumping and runoff from landfills, among other routes.
The challenge is clear. Reducing the amount of plastic waste would mean less plastic makes it to the world’s waterways. There are several ways to address that:
- Increased recycling; with less material discarded as intact plastics, there is less opportunity for synthetic plastics to make it into the marine ecosystem.
- Switching to bio-based materials that can degrade in the ecosystem.
- Incorporating sustainability into polymer manufacturing.
All three are needed, but that last idea offers perhaps the most exciting promise, even offering the potential to convert plastic waste from a problem to a solution.
At the least, we clearly should do better than recycling only 10% of all discarded one-time use plastics, but that will require meeting challenges and opportunities that are technological, economic and most importantly, behavioral.
Technologically, in most cases reusing plastics leads to a degradation of the material properties, resulting in downcycling the materials to lower value products.
That downcycling through traditional recycling routes, along with the intrinsic costs of collecting, cleaning and sorting prior to remanufacturing of the plastic materials, makes plastics recycling cost-prohibitive and an unattractive proposition. One potential solution is finding ways to use the embedded energy in those discarded plastics without the challenges of downcycling, while managing the costs of handling the plastics from consumer to recycled material.