Why is Recycling Plastics More Difficult than Any Other Material?

The US recycles less than 6% of plastics annually. Plastic bottles such as soda bottles and milk jugs are the most recyclable plastics, yet less than 30% of these plastics are recycled each year. The sad truth is most plastic products and packaging end up in landfills, incinerators, or litter in our environment. 

Nevertheless recycling plastics can have significant environmental benefits. Recycling PET and HDPE plastics can save 75 to 88% of the energy used to make virgin plastics and reduce GHG emissions by 70%. Recycling plastics also reduces air and water pollution compared to virgin production and reduces the need for more fossil fuel extraction to make more plastics. 

So if recycling plastics reduces fossil fuel consumption and is good for the environment and our climate, why aren’t more plastics recycled? The short answer is recycling plastics is complicated, much more complicated than recycling paper, metal, or glass. 

What makes something recyclable?

To understand why plastics recycling is so complicated, let’s first step back to establish what makes something recyclable. In order for something to be recycled, it must meet the following criteria: 

• It must be designed for recovery with some standardizations to ensure that all uses of the same material to make different products are still compatible with each other for recycling.
• There must be end markets, ideally created by the industry producing the item, that buy back the recycled material and are transparent about what products the material will be made into. 
• The material must be high quality enough that it can be recycled multiple times, even infinitely, as is the case with glass, steel, and aluminum. 
• There must be cost-effective value to efficiently collect, sort, and ship the material—the sale of the material must be greater than these processing costs. 
• There must be sufficient market value for the material that is high enough to incentivize the market to buy and use the recycled material for remanufacturing. 
• It must be clear to the consumer that the material belongs in the recycling bin.  

Why are so few plastics recyclable? 

Unlike aluminum, steel, paper, and glass food and products that generally meet the above criteria to be considered “recyclable,” plastics products fail to meet the same criteria on multiple fronts.

Bad design.  Most plastics packaging and products aren’t designed to be recycled. There is little standardization, but rather seven different resins; within those resin numbers, there are varying applications of more than 3,000 chemicals, toxic additives, dyes, and labels. The markets that buy recycled plastic cannot accommodate all of these inconsistencies in their formulas to create new plastics. The chemicals, additives, dyes, and labels contaminate new products and add further complications to plastics recycling because of the need to manage these byproducts in the recycling process. 

Many plastics also contaminate other high-grade materials during the sorting process. 

For example, plastic bags are the most costly contaminant in materials recovery facilities (MRFs) because they clog up the machinery, causing delays and potential damage. 

Few buyers. The market for recycled plastics is poor. Unlike the aluminum, glass, steel, and paper industries, the plastics industry does not buy back its recycled products, despite voluntary commitments by many leading brands for decades. For example, on average, plastic beverage containers are made from less than 10% recycled content, despite leading manufacturers like Pepsi Cola and Coca-Cola committing to greater use of recycled plastic since the 1990s. In the absence of industry buy-back, recyclers rely on selling to niche markets, making products like carpeting and clothing that cannot come close to purchasing the volume of recycled plastic on the market.

Low-quality material. Even those plastics like PET and HDPE that are recyclable can only be recycled a few times because the plastics break down throughout the recycling process. Nearly all plastics are downcycled into products that cannot be recycled again–for example, a recycled PET bottle may likely be made into a carpet, but the carpet will likely end up in a landfill at the end of its lifecycle. While metal and glass can be recycled indefinitely, plastics are only recycled a few times at most, which means more fossil fuels will be used to make new plastics in the future. 

Costly to collect and sort. Manufacturers are continuously changing the resin type, chemical additives, shape, and color in plastics packaging, forcing recycling facilities to constantly react to an ever-changing stream of materials which may necessitate the purchase of very expensive new sorting equipment and improved technology to sort plastics effectively. The market value of recycled plastic is not enough to cover these ongoing investments. 

Insufficient market value. Government subsidies for fossil fuel production and fracking falsely shift the economics of recycled plastic and make virgin plastic cheap to produce. The market value of recycled plastics cannot compete—the sale price is not always sufficient to cover the costs of sorting, collecting, and shipping the material. 

Misleading labeling. The end market for plastics is dependent on the plastic type, indicated by the number stamped onto most plastics. Unfortunately, the recycling symbol on many plastics is misleading. Only a few plastic resins can be successfully sorted and sold to an end market to be recycled into new products; many others are problematic and unnecessary due to resin type, toxicity, additives, or difficulty sorting.