Polyester isn’t just helping fuel the climate crisis, a new report warned Tuesday, but it could also be threatening human health.
This goes for both virgin and recycled versions of polyethylene terephthalate, better known as PET, according to Defend Our Health, a Maine-based nonprofit that focuses on food, water and product safety. Of the hundreds of chemicals that go into churning out plastic soda bottles, sweat-wicking yoga pants and wrinkle-free button-downs, many are highly hazardous, it noted.
“Petrochemicals are part of 99 percent of all PET produced,” research analyst Roopa Krithivasan, who co-authored the study, told Sourcing Journal. More PET plastic, she noted, is produced and consumed than any other single type of plastic. More than 83 million metric tons of PET were produced in 2019, accounting for about 19 percent of all plastics production. Two-thirds of all PET is channeled into polyester for clothing and other textiles.
Two of the biggest petrochemical building blocks used to make PET are monoethylene glycol and paraxylene. The first is a known fetal poison. The latter, a neurological and respiratory toxicant.
To speed up the final chemical reaction that produces PET resin and polyester fiber, antimony trioxide is frequently employed. Excess exposure to antimony compounds, some researchers have found, can result in health problems such as heart disease, liver toxicity and cancer. It’s for this reason that the heavy metal substance has been flagged by California’s Proposition 65 and the European Union’s REACH program.
Antimony is used in “most PET and polyester, which means it also remains in the plastic products and in the fabrics that we use,” Krithivasan said.
The chemical can leach from the plastic itself, she added. When Defend Our Health tested plastic containers from 20 major beverage brands, nearly half (40 percent) contained concentrations of antimony in the drinks themselves that exceeded 1 part per billion, the California Public Health Goal for contaminants in drinking water.
Though Defend Our Health didn’t test any textiles, Krithivasan said she wouldn’t be surprised if it found a “similar pathway” of contamination. Antimony, which is added to many other plastic products, including electronics and home furnishings, is regularly detected in household dust. Embedded in sloughed-off microfibers, where it can be ingested or inhaled, antimony in polyester contributes to what she calls the “aggregate risk” of worsening overall impact. Children, with their developing bodies, are especially vulnerable.
“When we take urine samples and look at what’s in our bodies, we find that the levels of antimony in the bodies of children are much higher than they are in adults, at levels that far exceed what the U.S. EPA and the California EPA consider safe,” Krithivasan said. “So we have this chemical compound being used all over the place in PET and polyester manufacture. It’s showing up in our food and clothes, it’s showing up in our bodies. And yet we just carry on as though PET plastic and polyester are totally safe.”
As apparel brands scramble to achieve ambitious sustainability goals, many have turned to recycled polyester as an alternative. But Krithivasan said this does not address the “basic chemistry” of these products and the fact that they are “highly toxic” throughout their manufacture and life span.
Another reason to be a “little bit skeptical” of fashion’s embrace of recycled polyester is that shortened staple lengths from mechanical methods could result in more heavy microplastic shedding, though more research is needed before this can be stated definitively.
“I do think it warrants a much closer look to see if both antimony in recycled products is higher and also if microplastics shed antimony more in recycled products,” Krithivasan said.
What’s less up for debate is the fact that PET production can contribute to environmental racism and injustice, Defend Our Health said. The report identified nearly 50 chemical plants, antimony processors and plastics factories that pump out PET plastic and polyester in North America. Compared with the average U.S. population, the people who live within three miles of most of those industrial facilities are often low-income or non-white.
The burden on such communities would increase if two proposed petrochemical plastic plants go online. Corpus Christi Polymers has its eye on a giant PET plastic plant in Texas, which if approved would increase North America’s capacity by nearly 25 percent. Formosa Plastics’ planned $9.4 billion chemical facility in Louisiana’s St. James Parish is poised to generate an annual 1.6 million tons of PET-producing monoethylene glycol.
“These are largely communities of color that are facing many injustices due to the way petrochemicals have absolutely exploded in that region, including the chronic health effects of living near these massive polluters,” Krithivasan said of the cluster of petrochemical factories in the Gulf Coast derisively known as “Cancer Alley.” “And yet there are plans to scale up PET and polyester production in the United States.”
There are actions companies can take to immediately mitigate some of the harm, such as switching to a less toxic catalyst. This requires some tradeoffs, however. Germanium oxide, for example, harbors low toxicity, but it’s more expensive and harder to come by. Biobased enzymes or other organic biocatalysts could be the safest solution, but they’re not yet commercially available for PET polymerization.
In the long run, Defend Our Health recommends phasing out PET and polyester altogether, with recycling only as an “interim step” on the road to true sustainability. The industry isn’t bound to polyester as a textile material, since natural options exist, Krithivasan said. Ultimately, the industry must reduce synthetic fiber production. And fashion, for its part, should be brainstorming ways to stop using plastic to make the bulk of its clothing. According to Textile Exchange, polyester accounted for 52 percent of global fiber production in 2020.
“I think there’s enough to suggest that they just don’t belong in our lives,” she said. “There are absolutely some uses, like in medical facilities or where you can’t find a replacement for them. But apart from that, there is no need for these plastics to exist in our lives. It doesn’t matter if they’re recycled, it doesn’t matter if they’re virgin. They’re just not good news.”