Single-use bottles, wrappers, and containers are often simply discarded—but reforms that could make them infinitely recyclable are on the horizon.
Written by: ALEX WHITING | SCIENCE
PET plastic bottles await recycling TOMOHIRO OHSUMI/BLOOMBERG VIA GETTY IMAGES
Walking down the street, or visiting the park or beach, there’s one thing you’ll almost inevitably see: pieces of plastic packaging—washed up on the sand, tangled in a hedgerow, lying in the gutter.
Plastics are polluting all corners of the planet, from the Arctic to the ocean depths, with as yet unknown consequences for human health. Already 11 million metric tons of plastic waste enter the oceans every year. Without radical change, the amount of plastic waste generated worldwide could double by 2040 and, if waste infrastructure can’t keep up, the amount of plastic entering the ocean will nearly triple, according to research by the Pew Charitable Trusts.
In the battle to stem the tide of plastic waste, companies and academics are developing new ways to reduce plastic packaging—the single largest source of this waste. Clever designs for alternative materials abound, including edible water containers made from algae, compostable packaging made from fungi, and water bottles constructed out of paper. “There is a lot of space for shifting plastic packaging to other materials,” says Jim Palardy, project director of Conservation Science at Pew, and a coauthor of a report that assesses ways to end plastic pollution.
But inroads made by such substitutes are not yet enough to end our enormous reliance on plastic. Plastics production has almost doubled since 2000, and is expected to grow significantly in the next 20 years, according to the International Energy Agency. And the track record of where these materials tend to end up isn’t great. Up to 2018, about 80 percent of all virgin plastics ever produced had wound up either in landfill or in the natural environment.
Despite the gloomy statistics, our addiction to plastic packaging is not all bad, says Richard Thompson, director of the Marine Institute at the University of Plymouth. Plastic is lightweight, highly durable, inexpensive, and very versatile. “Although I’m a marine biologist that works on the impacts of plastic in the ocean, I actually think plastics are really wonderful. It’s just that we’ve failed to use them responsibly.”
The solution to the plastics problem, Thompson argues, lies in plastics themselves: “Before we start looking for other substances, we need to do a much better, more responsible job of what we do with the material we have already got.”
This means designing plastic packaging so that it’s easier to recycle. Plastics are made of large molecules called polymers, with different plastic types made up of different ones. The plastics most commonly used in packaging are polyethylene (of various densities), polypropylene (PP), polyethylene terephthalate (PET) and, to a lesser extent, polystyrene (PS) and polyvinyl chloride (PVC).
The easiest to recycle are PET and high-density polyethylene (HDPE), which are used to make soft drinks bottles or containers. What makes recycling difficult is when different plastic types are used together, as well as the sheer variety of plastic on the market, as different types have to be separated to be recycled. (Research into recycling different plastics together is underway, but still at an early stage.) So reducing the diversity of plastic polymers used would make recycling much easier and more cost effective.
“We’ve got thousands of different polymer permutations,” says Thompson, even in single-use plastic packaging, which comprises 40 percent of all the plastic made. “We could probably do most of the heavy lifting for all of the single-use packaging with two or three different polymers,” he says.
Companies are now beginning to respond to this challenge. “You need to go to one rough polymer design while maintaining the functionality,” says Marco ten Bruggencate, a commercial vice president for packaging and specialty plastics at Dow, one of the world’s biggest chemical companies. That “functionality” includes preserving whatever product is in the container while maintaining its brand appeal. Dow mainly produces polyethylene (PE) for packaging, a plastic which can be used to make containers for a wide variety of products, from shampoo bottles to food packaging film.
Manufacturers know how to make between 80 percent and 90 percent of all packaging recyclable, says Ten Bruggencate. But solutions still need to be found for the remainder, such as packaging for cheese and meat. The challenge here, Ten Bruggencate says, is creating packaging that keeps meat fresh, but which is made from one-polymer polyethylene rather than a complex structure of different polymers. “You need to be able to innovate to enable all these functionalities within one polymer,” he says.
Other businesses are boosting recyclability by using more clear plastic.
Drinks bottles are made of easy-to-recycle PET, but if dye is added to them, the colors merge during recycling and produce a gray recyclate that is hard to then sell. “Recyclers tell me the clear PET bottle is worth twice as much to them,” Thompson says. Coca-Cola is rolling out clear bottles in North America made from 100 percent recycled PET. It’s already using clear bottles in Asia and Europe.
CHANGING THE MAKE-UP of plastics is one part of the equation. But there’s also a lot else that needs to be done to get more plastic reused. The converter industry—which takes recycled plastic and forms it into whatever a brand needs—will need new machinery to handle simplified plastic resins made from simple polymers. So scaling packaging that is close to 100 percent recyclable will take a few years. “By 2025, you will have a much more mature industry with respect to design for recyclability,” says Ten Bruggencate.
By then it will be vital to improve waste collection and recycling infrastructure so it can handle the waste. Recycling levels are very low in many parts of the world. In 2018, Europe collected just 32 percent of its 29 million metric tons of plastic waste for recycling, according to the European Environment Agency. That same year, the plastic recycling rate in the United States was less than 9 percent. This is particularly bad given the US and UK produce the most plastic waste per capita in the world.
Many brands have set their own targets to increase the use of recyclable plastics or recycled content. Brands are shifting to recyclable materials under pressure from consumers and government regulations.
For example, the European Union aims for all plastic packaging to be reusable or recyclable by 2030. It is also expected to set a target soon for plastic packaging to comprise 30 percent recycled material—a move supported by European plastics producers. This should strengthen the market for recycled plastic.
But to create a system in which plastics can be continually recycled, the very process of recycling is going to need an upgrade too. Typically plastics are recycled “mechanically”—they’re washed, ground down, and melted into granules, which are then used to make new plastic items. The chemical structure of the plastic doesn’t change significantly—it will still be made of the same polymers (so if you mechanically recycle PET, you produce more PET). However, the process causes the plastic’s polymers to degrade and lose strength. This means plastic can only be mechanically recycled a few times.
To truly be used over and over, plastic would need to go through chemical processing to convert it into basic chemical building blocks, from which different plastic types can be made. Such chemical recycling is possible, but still relatively new. “The technology is there—we just need to make sure it’s bulletproof,” says Ten Bruggencate.
That said, he thinks that mechanical recycling should always be prioritized, because “that’s the easiest thing you can do”—only when a plastic can’t be mechanically recycled should it be chemically recycled.
But the benefits could be big. The production of brand-new plastic and its conversion to specific plastic types is responsible for 80 percent of plastic’s life-cycle emissions. Avoiding making virgin plastics from fossil fuels will therefore be key for the plastics industry to reduce its carbon emissions and reach net zero, Ten Bruggencate says.
Plastics producers are spending billions on researching these chemical recycling technologies. Members of Plastics Europe, a trade association of plastics manufacturers, have planned investments in chemical recycling technologies and infrastructure of €7.2 billion up to 2030.
The European Environment Agency says that chemical recycling offers potential new ways of recycling products that are difficult to recycle mechanically—including plastics mixed with other materials or types of plastics, or which are contaminated by hazardous chemicals. However, it notes that there’s little knowledge about the impacts of chemical recycling on the environment—both in terms of the energy needed to run it and the waste products it produces.
“If chemical recycling is to become a more widely used technology, it will be important to explore the environmental and climate implications and risks as well as the financial costs in more detail, to determine whether there is an overall benefit to this type of recycling,” the agency said in a 2021 report.
JIM PALARDY OF PEW is hopeful that plastic waste can be reduced to a trickle within 20 years. His report found that it’s possible to cut all plastic waste flowing into the ocean by 80 percent in the next 20 years using existing solutions and technologies. “The most important solutions really aren’t rocket science,” Palardy says. As well as better waste management and recycling, hitting this reduction would require making sure that all the plastics we do need are recyclable, avoiding single-use products whenever possible, and replacing plastics with paper and compostable materials—or other materials which are easier to reuse or recycle.
So those substitute materials—the algae and fungi containers and paper bottles—will have some role to play. But with substitutes, the devil is in the detail to ensure that they don’t create new problems. Paper will need to come from sustainably managed forests, and the necessary waste facilities are needed to deal with substitutes that have to be industrially composted.
Then there’s the risk of increasing greenhouse gas emissions. Substitute plastic with glass, for example, and you increase transport emissions, because heavier products require more fuel to move. But if the glass could be transported using renewable energy sources, “the maths changes in a big way,” Palardy says.
One of the most important solutions, though, is to get rid of superfluous plastic altogether. There are many opportunities to do this. Selling shampoo in solid bars removes the need for a plastic liquid container. Another easy win is to use stand-up flexible plastic pouches for liquids. These use 60 percent less plastic than rigid plastic bottles. But although this offers huge savings in plastics and carbon emissions, companies are shifting to pouches “very, very slowly,” says Ten Bruggencate.
Overall, making the changes necessary to stem 80 percent of plastic pollution entering the ocean by 2040 is possible, says Palardy. “It’s not going to be easy. But we know how to do it.” As for the remaining 20 percent, “there are a lot of people working on this problem—and so that really does give me hope,” he says.
Reaching net zero emissions by 2050 will require innovative solutions at a global scale. In this series, in partnership with the Rolex Perpetual Planet initiative, WIRED highlights individuals and communities working to solve some of our most pressing environmental challenges. It’s produced in partnership with Rolex but all content is editorially independent. Find out more.
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