If you've ever looked at the bottom of a disposable bottle or cup, you've probably noticed this symbol. Seeing this, many people assume the item they’re holding should be tossed in a recycling bin. Yet many of these plastics are incapable of being recycled at most centers. In fact, of the 360 million tons of plastic created worldwide each year, only 9% is ever recycled. So why are so few plastics recycled? And what do these codes actually mean?
Our recycling problem is multi-layered, beginning at production.
About 18% of plastics are made from what is known as thermosetting polymers. These plastics gain stability through curing, a process that hardens a material by irreversibly crosslinking its molecular chains. The very properties that make thermoset plastics so useful, in that they keep their shape and integrity under extreme conditions, mean that they can’t be broken down and rebuilt by the vast majority of recycling plants.
Thankfully, most plastics are thermoplastics, which can be melted and remolded. But this category encompasses a variety of materials with unique chemical structures, weights, and properties, all of which require different conditions for recycling. As a result, only some of these thermoplastics are accepted at most recycling centers.
Which brings us to our next problem: the confusing code system.
Developed and introduced by the plastics industry in 1988, this code was presented as a way to help consumers and facilities sort their trash. Each number indicates the material the plastic is made of, known as its resin. Some resin numbers are recyclable at most centers, while others are not. And yet, within this system, all numbers are surrounded by the universally recognized recycling symbol, misleading consumers into thinking that many unsalvageable plastics have a chance at a second life.
And just because a technically recyclable resin makes it to a recycling bin, doesn’t mean it will continue its journey. Plastics often contain multiple resins, are mixed with dyes and additives, or are affixed with difficult-to-remove stickers and labels, all of which can cause them to be rerouted to the incinerator or trash bin. In short, many companies don't design packaging with recovery in mind.
Even under pristine conditions, plastic resins can only be melted down and remolded a handful of times, as their polymers degrade with each use.
If all these issues make you feel as if recycling plastics is infeasible, you wouldn't be the first. This reality was well known to the plastics industry as early as the 1970s. Despite their doubts that widespread recycling would ever be economically viable, the industry threw millions of dollars into ad campaigns. Within the US, the plastics industry quietly lobbied state governments, leading a majority to adopt laws requiring that plastics bear the confusing resin codes. And with this, the burden of “fixing” the growing plastic waste problem was pushed from the industry onto the consumer.
Today, the situation has only gotten worse. The rising costs to properly separate all this waste, paired with fewer international buyers of recyclable scraps, has forced many cities to shut down their curbside recycling programs altogether.
So how can we fix our growing plastic waste system?
It’s clear that we must reduce the plastics we consume. More than a quarter of our plastic waste comes from packaging materials. Many manufacturers have taken steps in the right direction, phasing out unnecessary plastic films, and switching out plastic tubs and tubes with more easily recyclable materials, or compostable options.
For the plastics that do remain, one solution is to work towards a circular economy for plastics. This means creating fewer new plastics, eliminating those that are single-use, and ensuring the plastics that remain can stay in circulation via recycling. Such a system would rely on policies that regulate plastics starting at their production— ensuring that all plastics created are free from contaminants that could harm their ability to be recycled.
In the meantime, many experts believe the current resin code system should be eliminated, and swapped out for clear, simplified recyclable versus non-recyclable labels. This would help consumers more easily sort their waste, but more importantly, allow them to make informed decisions at purchase, ultimately putting the pressure back on manufacturers to ensure a recyclable future.
