Plastics are inescapable. That soda bottle or disposable razor or even the coating on your mattress may expose you to hundreds of different chemicals, some of which scientists know very little about. Scientists are now a step closer to handling this complexity. On Thursday the PlastChem Project, a group of researchers in Norway and Switzerland, announced that it had identified more than 16,000 chemicals in plastic products in the first comprehensive database of all known plastic chemicals. The database, accompanied by a report, sorts the chemicals by their known environmental and health effects—a bank of information the PlastChem team hopes will inform governmental regulations, as well as international negotiations for a treaty to curb plastic use and production.
“It’s a dynamite report,” says Miriam Diamond, who studies chemical contaminants at the University of Toronto and was not involved in the research. The new database brings together information from scientific papers and seven datasets that detail different chemicals, says Martin Wagner, PlastChem’s project lead and a biologist who studies plastics at the Norwegian University of Science and Technology. It took his team about a year to compile and sort through all the data. A 2023 report from the United Nations Environment Program had previously estimated there are more than 13,000 chemicals associated with plastics. The new database expands this to a degree that shocks even scientists who study these issues. “Sixteen thousand chemicals—oh, my God,” Diamond says.
In addition to the sheer volume of chemicals, “the striking thing for us is that at least 25 percent of these are chemicals of concern,” Wagner says. The researchers zeroed in on more than 4,200 of the chemicals in the database that they flagged for several qualities: the chemicals’ tendency to persist without degrading, ability to build up in the human body or other organisms, mobility through the environment and toxicity.
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The chemical complexity of plastics has posed challenges in fully understanding their health and environmental effects—about 10,000 of the chemicals in the new database did not have sufficient information to determine their potential risks. But for some of them, there is strong evidence of health risks. Phthalates—used in coatings and flooring materials to make them thin and flexible—disrupt the reproductive system, Diamond says. Her research has also shown that exposure to phthalates in household dust in a child’s first year of life is linked with increased risk of asthma at age five. Bisphenols, including bisphenol A (BPA), are another group of plastic chemicals that are well-known for disrupting the body’s hormonal regulation. And then there are perfluoroalkyl and polyfluoroalkyl substances, or PFASs, which have been linked with cancer risk and immune system problems.
Wagner says he was surprised to learn about the risks associated with melamine. This material is used to make bowls and other dinnerware; it’s also combined with bamboo and other natural organic materials to make plastic alternatives. Melamine is classified as a carcinogen by the European Union and has been detected in drinking water, yet it is widely used. The chemical also readily moves through the environment, and it’s highly resistant to degradation.
The report also highlights the continued presence of chemicals, including polychlorinated biphenyls (PCBs), that have been banned in plastics under the U.N.’s 2001 Stockholm Convention on Persistent Organic Pollutants, which went into effect in 2004.
The health problems linked to plastic chemicals are a significant burden on society, Wagner says. A study published in January estimated that the annual health-related costs attributable to exposure to four types of plastic chemicals—including phthalates, bisphenols, PFASs and flame-retardant chemicals called polybrominated diphenyl ethers (PBDEs)—cost $250 billion per year in the U.S., about 1.2 percent of the nation’s gross domestic product. Exposure to these chemicals is associated with health problems, including developmental disorders, cancer, diabetes and infertility. “It sounds very scary and frustrating,” Wagner says. “But there are opportunities here to put plastics on a safe and sustainable pathway so that we don’t have to pay all these costs.”
The PlastChem report recommends a few solutions. First, more information is needed on the 10,000 plastic chemicals that are insufficiently studied. “We urgently need some action on filling those data gaps,” Wagner says. This could take decades even with ample scientific funding. The report’s authors recommend prioritizing research on understudied chemicals based on the size of the market for them. The authors also push for a regulatory approach called “no data, no market,” which would put the onus on companies to provide toxicity data about chemicals before they can sell products that contain them.
Wagner and the PlastChem team also recommend simplifying plastic recipes. There are about 3,000 chemicals used as dyes, for instance. This list could be streamlined to reduce potential health and environmental impacts. Simplifying plastics’ chemical footprint would also make it easier to recycle them. And the report calls for more transparency about what’s in plastics. Currently scientists must perform an intensive chemical analysis to find out what ingredients are in a given plastic product, what their concentrations are and whether they pose risks.
In an e-mail to Scientific American, Matt Seaholm, CEO of the Plastics Industry Association, an industry trade group, took issue with the premise of the report. “Plastic as a material continues to offer safety, protection and efficiency while also being able to be reused and recycled,” Seaholm wrote. “Chemicals are chemicals and policies should be developed that are applicable to all of them. Trying to focus exclusively on ‘plastics chemicals’ risks redundancy and tunnel vision in policy.”
Global plastic recycling rates are as low as 9 percent, according to the Organization for Economic Co-operation and Development. Only 15 percent of plastic waste is collected for recycling, but 40 percent is discarded from the recycling process because of its low quality. If this continues, plastic pollution in aquatic ecosystems could triple from nine million to 14 million metric tons in 2016 to 23 million to 37 million by 2040.
And as the PlastChem report highlights, scientists believe there is too little information in what is in all this plastic. “We don’t have enough research on plastic chemicals,” says Christopher Reddy, a marine geochemist who studies plastic pollution at the Woods Hole Oceanographic Institution and was not involved with the report. “As we move forward, we need to identify the safest and most sustainable plastics and be strategic in the way we choose which polymers and which additives we need.”
The PlastChem team hopes the database will provide guidance to policymakers heading into the next round of negotiations for an international plastics treaty that is overseen by the U.N. Environment Program’s Intergovernmental Negotiating Committee on Plastic Pollution. Delegates at the meeting will discuss ways to limit plastic pollution by focusing on the entire life cycle of plastics: ways to regulate how they are designed and manufactured, as well as how to ensure that they are recycled. The High-Ambition Coalition to End Plastic Pollution, led by Norway and Rwanda, is pushing to ban or restrict production of problematic plastics and develop sustainability criteria, among other goals. The chemical industry has been pushing back on these efforts, asserting that the focus should be on recycling, not production. Scientists who study the plastic waste problem and environmental groups highlight that recycling is insufficient because of low rates, the inability to recycle some plastics and the fact that all the chemicals in plastic mean products made from recycled materials are of lower quality. The treaty negotiations will be held in Ottawa in April and may be finalized at the end of this year at a meeting in Busan, South Korea.
“There’s a need for governments to act, and they have the opportunity to do it now,” Wagner says. “We need a systemic political solution.”