Plastics additives understanding lacking during treaty talks, study says

A new science report is pushing for the plastics treaty to include tougher regulations and greater public disclosure on chemicals of concern to human health and the environment that are used in making plastic.

The March 14 report from the PlastChem Project, a group of academic, science and food packaging groups, said it wants to give negotiators of a United Nations plastics treaty a scientific framework for evaluating thousands of chemicals used in plastics manufacturing, including additives, processing aids and impurities.

The report, combined with a somewhat similar transparency project underway within the plastics industry, suggests the treaty could likely include at least some calls for public transparency around additives in plastics.

The report's authors want to go further and adopt a new regulatory approach.

The PlastChem researchers said they've identified 16,000 such chemicals — up from 13,000 substances pegged in a 2023 United Nations report — and said 26 percent of them are "of concern because of their high hazards to human health and the environment."

"The PlastChem report is a wake-up call to policymakers and industry," said Hans Peter Arp, a co-author of the report and professor at the Norwegian University of Science and Technology. "We need more transparency and better management of chemicals of concern in plastic. The future of innovation in plastic should focus on safety, sustainability, and necessity, rather than just functionality."

The PlastChem Project, which includes funding from the Norwegian Research Council, includes a public database for those 16,000 chemicals.

With the plastics industry preparing to release its own public datasets, it seems likely the plastics treaty will endorse or include measures to step up scrutiny of chemicals used in plastics.

The International Council of Chemical Associations, for example, plans to release the first version of a public database of additives this year that will include the use, function and hazard data for additives used in commerce over the last 10 years.

Kimberly Wise White, vice president of regulatory and scientific affairs for the American Chemistry Council, said ACC welcomed the PlastChem report's call for more transparency around additives, and she pointed to the ICCA project.

But she also said the additives have important benefits, like extending the life and durability of plastic products such as wind turbines or improving packaging to prevent food spoiling.

And she criticized the report for adopting a hazard-based, rather than a risk-based, approach to assessing safety.

"Unfortunately, today's report seeks to advance a hazard framework that ignores real-world exposures and paints an incomplete picture for regulators and the public," White said. "This contrasts with risk assessments used to underpin the most effective chemical management laws."

She said the report also disregards work underway at another United Nations agreement, the Global Framework on Chemicals, that is implementing a regulatory approach to evaluate "all uses of a chemical, not just their use as plastic additives."

White said the global chemical industry is supporting the buildout of chemical management capacity in 30 countries by 2030 where such regulations do not currently exist.

"The report's recommendation to regulate plastic additives using a hazard-based approach undermines the stated purpose of the report to use an 'evidence-based path forward,'" White said.

But the PlastChem report said new approaches are needed to regulate chemicals in plastics, including a hazard-based identification of groups of plastic chemicals.

The report's researchers said a group approach is needed in regulation because of the volume of chemicals that need to be assessed.

"Besides the high numbers of known chemicals, plastics can also contain and leach unknown substances, such as contaminants, impurities or degradation products," said Ksenia Groh, a report co-author and a bioanalytic researcher at the Swiss Federal Institute of Aquatic Science and Technology.

"The toxicity of overall chemical mixtures leaching from plastics can be evaluated using bioassays, and we reviewed this in the PlastChem report," Groh said. "Importantly, many plastic products showed high toxicity in ... evaluations."

Researchers said they see the report as providing a path to "simpler and safer" plastics.

"This report is unique," said Jane Muncke, a report co-author and managing director at the Food Packaging Forum. "It's a systematic, comprehensive approach to understanding the chemical dimension of plastics, and it offers robust, science-based and future-proof options for responding to this challenge."

The report's authors said they could not find hazard data on more than 10,000 of the 16,000 chemicals, with data suggesting that 4,200 of them are hazardous for the environment or people.

Martin Wagner, the coordinator of the PlastChem Project and the report's main author, said significant gaps in the global regulatory structure point to the need for more action.

"We want to create safer and more sustainable plastics," Wagner said on a March 14 webinar launching the report. "Plastic chemicals of concern are really a roadblock in such a transition."

He said the project recommends a hazard-based approach for regulation, including regulating them in groups, because of the volume of chemicals that must be assessed. A risk-based approach would require too many resources and could lead to delay, he said.

The report recommended 15 group categories, including some categories researchers on the webinar said have received a lot of attention like phthalates and PFAS, but also those with less attention, including aromatic amines.

"The idea of that approach is to address groups of chemicals of concern, instead of individual chemicals," Wagner said. "This is backed by scientific evidence because we know that a similar chemical structure often comes with similar hazard properties."

"We believe such a group-based approach will also incentive safer designs of chemicals and avoid what we call regrettable substitutions, because it takes away the opportunity to use problematic chemical structures," Wagner said.

The Business Coalition for a Global Plastics Treaty, a group of consumer product makers and financial institutions who are part of the treaty talks, spoke during the webinar and said they want the agreement to include specific ways to develop lists of chemicals to phase out.

"When we look at the treaty, we're hoping there will be alignment on binding harmonized criteria, that the annexes will provide space for the development of specific lists of chemicals, groups of polymers and chemicals that should be phased out," said Jodie Roussell, a Nestle executive who was speaking for the business coalition.

She did not comment in detail on the PlastChem report but said the business coalition released a detailed position paper in January, ahead of the next round of talks, on chemicals and polymers of concern and approaches in the treaty.