Editor’s Letter: Making Sense of Numbers

The writer and humorist Mark Twain observed that “Clothes make the man. Naked people have little or no influence in society.”

Twain was speaking in the 19th century. In the 21st century, a similar thought can be expressed about numbers, especially statistics, which activists recite on cue when promoting causes like plastics regulation or bans.

The ability to recite numbers about the volume of plastics production, the tally of plastics in products, the number of disposable packages in circulation, the plastics trash that ends up in landfills or as litter and the lack of recycling infrastructure is the sine qua non of regulatory arguments. It’s almost like saying people without numbers have little or no influence on society.

Statistics, of course, can be an important first step in identifying issues, challenges and objectives. Most people in the industry know that only 9 percent of all plastics worldwide are recycled every year, and even less in the U.S.; and 80 percent of ocean plastics pollution begins with improper disposal of waste on land. These numbers are unacceptable and cause for concern.

But statistics can also be irrelevant, especially when presented without context. In March, a USA Today columnist wrote that “Humans have produced 18.2 trillion pounds of plastics—the equivalent of 1 billion elephants (emphasis mine)—since large-scale production began in the early 1950s.”

18.2 trillion pounds is quite a number; inconceivable, in fact, to many people, but perhaps not so overwhelming if expressed as a more manageable 9.1 billion tons, or better yet 9.1 x 10⁹. The number, no matter how one expresses it, also reflects the availability, application versatility, economy and benefits of one of the 20th century’s miracle materials, one that has driven advances in markets as diverse as packaging, medical, automotive and electronics, and which continues to improve the standard of living for most of the world’s 8 billion people. A world without plastics is not unimaginable; it’s undesirable.

Numbers like these, moreover, never convey the gains that the industry makes in confronting issues of recycling, sustainability and creation of a circular plastics economy. In April, the month set aside for Earth Day, the journal Nature published a research paper that showed promising results in efforts to create a fast-acting hydrolase for enzymatic depolymerization of polyethylene terephthalate containers and bottles. PET is considered one of the “problem plastics” by activists, owing to its widespread use in single-service containers and prevalence in waste streams and ocean pollution.

The paper is titled “Machine learning-aided engineering of hydrolases for PET depolymerization.” Research was conducted at the University of Texas, Austin. Contributors to the project included ExxonMobil Research and Engineering Co. (funding), the National Institutes of Health (a grant) and the Texas Advanced Computing Center in Austin.

The researchers formulated a “robust and active PET hydrolase” they named FAST-PETase (functional, active, stable and tolerant). The hydrolase was developed with a machine-learning algorithm that produced a biochemical catalyst with superior PET-hydrolytic activity. The FAST-PETase enzyme was effective at almost completely degrading thermoformed trays with varying pH levels in one week, at process temperatures of 30 to 50°C (86 to 122°F). The algorithm established five mutations needed in the enzyme to rapidly degrade PET.

FAST-PETase also depolymerized amorphous portions of a commercial water bottle and an entire thermally pretreated water bottle at 50°C.

The researchers described a closed-loop process akin to advanced or chemical recycling, in which FAST-PETase depolymerizes PET and resynthesis of the constituent monomers occurs.

As promising as this and other research into recycling and sustainability is, activists will never cite it as an example of the industry’s commitment to improving the environmental footprint of plastics. This vision of plastics contradicts the restrictive outcome many activists want. The technology is also difficult to explain in debates and less compelling as a call to action than beaches and oceans littered with waste.

The plastics industry should aggressively promote such research, commercialize it as soon as possible, and show consumers and regulators that plastics are not a burden on the future, but a necessary and positive means of maintaining progress in numerous aspects of life.

Remember: Bad news sells. USA Today on Earth Day this year published another column on plastics that included this quote from one activist: “Most of all, plastic waste isn’t safely recyclable, and it is wrecking the recycling system.”