Food comes into contact with a lot more than plates and forks. Wrappers, takeout containers, storage tubs, cookware and manufacturing equipment can all contain chemicals that may eventually make their way into food.
Scientists already know that at least 2,160 chemicals can migrate from food-contact materials into food. But a new study suggests there are still major gaps in what researchers know about many of the chemicals used in or found in those materials.
Researchers analyzed 15,159 chemicals linked to food-contact materials and identified 1,222 with established hazards based on government and regulatory classifications. At the same time, 13,211, or 87%, had no standardized hazard data for the health effects included in the analysis.
That 87% figure needs some context.
It does not mean researchers found that 87% of food packaging chemicals are dangerous. It means they could not find the type of established, standardized hazard information needed to evaluate them using the system developed for the study.
The research, published in Environmental Science & Technology, was not a human health trial and did not test whether using food packaging causes cancer, reproductive problems or other illnesses. Instead, the researchers pulled together existing information about chemicals used in or detected in materials that touch food and developed a way to identify which ones may deserve more attention.
Among the 1,222 chemicals already classified as hazardous, researchers found substances associated with concerns such as cancer, reproductive effects, hormone disruption or damage to specific organs after repeated exposure. The list also included some chemicals that can persist or accumulate in the environment or body.
But identifying a hazard is not the same as determining a person's risk.
A chemical may have the ability to cause harm under certain conditions, but whether it poses a meaningful health risk also depends on how much someone is exposed to, how often the exposure occurs and how the chemical enters the body.
That distinction matters especially for food packaging.
For 94 of the hazardous chemicals, researchers found evidence that the chemicals can migrate from food-contact materials and have also been detected in people through biomonitoring programs. That group included lead, the PFAS chemical PFOA and the plasticizer DEHP.
Even then, the study cannot show that food packaging was the source of all or even most of a person's exposure. Many chemicals can come from multiple sources, and the amount that moves from packaging into food can depend on factors such as temperature, storage time, the type of food and how the material is used.
One of the researchers' biggest concerns is what can happen when a well-studied chemical is replaced with a similar but less studied one.
Bisphenol A, better known as BPA, is a familiar example. As concerns and restrictions around BPA grew, manufacturers began using alternatives such as bisphenol S, or BPS. But a replacement is not necessarily safer just because it has been studied less.
To help flag potential problems like that, researchers grouped chemicals according to similarities in their structure. They identified 38 groups they believe deserve particular attention, including PFAS, ortho-phthalates, organophosphates and several less familiar groups.
A total of 4,222 chemicals fell within those priority groups. Some are already known to have hazardous properties. For many others, the bigger problem is that the available information is incomplete.
That still does not mean every chemical within one of those groups is harmful. Structural similarity can help researchers decide what to study next, but it cannot prove that two related chemicals will affect the body in the same way.
The authors argue that grouping similar chemicals could make safety evaluations more efficient. Instead of waiting to examine thousands of chemicals one by one, regulators and manufacturers could give more scrutiny to groups that already include substances with known hazards.
The researchers also acknowledge significant limitations.
The list of chemicals associated with food-contact materials is likely incomplete. Some substances may never have been identified, and information about chemicals used during manufacturing is not always publicly available. The study also relies heavily on chemicals that have already received scientific or regulatory attention, meaning less-studied substances are more likely to have missing information.
The study therefore cannot tell consumers which packages or containers are "safe" or "unsafe," nor does it measure the health risk from using common food packaging.
Instead, it points to a broader problem: Scientists know a great deal about a relatively small number of food-contact chemicals, but considerably less about many others that may be present in materials people encounter every day.
The researchers say better testing, more transparency about chemicals used in food-contact materials and greater attention to groups of similar chemicals could help close those gaps.
The study was supported by the Environmental Defense Fund, the Food Packaging Forum Foundation using resources from unrestricted donations and the Minderoo Foundation, an Australian philanthropic organization. The authors said Minderoo and its benefactors had no influence over how the study was conducted or reported.