What Do We Really Know About The Chemicals In Food Packaging? 5 Questions With Dr. Birgit Geueke

January 23, 2023

By Alexandra Zissu, Editorial Director

Even if you grow your own veggies and shop for as much as you can at a farmers’ market, chances are some of your food is packaged. While there has been considerable focus of late on the ingredients in packaged food—what they are, are they safe?—there has been less on what the actual packaging is, and if it’s safe. This is a subject that is likely to take off in the year(s) ahead, as there are a substantial number of chemicals in these materials, all constantly in contact with our food. For some clarity, we reached out to Dr. Birgit Geueke, Scientific Officer, at the Zurich-based Food Packaging Forum for her take. Read on to learn about chemical migration, the unexpected hazards involved with recycled food packaging materials, and what parents can do to help protect their children.

1. Almost no food comes unpackaged these days. Are the various things being used for everything from cheese to meat to dried pasta truly safe? What are the concerns?

Food packaging allows the efficient handling, transport and storage of food, helps preventing food spoilage, and is a very suitable marketing tool. On the other hand, food packaging may release its chemical components into the food and thereby contaminate the food with chemicals. Many thousand chemicals are used to produce materials coming into contact with food during handling, storage, and packaging. By far not all of these chemicals have been tested for their safety. The safe use of many of the authorized chemicals may also be questioned according to new toxicological data. In addition, packaging materials usually contain non-intentionally added chemicals, which arise from impurities of the raw material, unwanted reaction products or break-down products. These chemicals add to the list of possible contaminants that may be released into the food. The majority of consumers are not aware of this issue, which we call chemical migration, and assume that food packaging is completely safe.

2. Who is studying food packaging? Are there any studies out there showing that farm to table eating-which involves very little food packaging-decreases the amount of food packaging chemicals found in our bodies and/or blood?

Many different interest groups are involved, e.g., food producers who want to extend the shelf life of their products or use the packaging for marketing purposes, packaging manufacturers who have to persist on a highly competitive market, legislators who set the regulatory framework, researchers who aim at innovative packaging solutions, consumer organizations who help to secure safe and sustainable packaging solutions.

Several scientific studies exist relating the contribution of packaging to the amount of specific chemicals measured in the bodies. Researchers reported decreased levels of BPA and phthalates in pregnant women of the Old Order Mennonite Community, when compared to pregnant women of a U.S.-wide survey. The consumption of fresh produce, which was not prepackaged or processed, was identified to be one of the reasons for the decreased levels of chemicals in the women from the community. In a second study, levels of BPA and one specific phthalate (DEHP) could be significantly reduced after three days of eating food with limited food packaging. However, not all phthalate levels could be decreased by this kind of diet, which might be explained by other sources of phthalates such as cosmetics or indoor air. In these cases, the differences in exposure caused by the packaging-free diet may have been too small to be measured.

3. We hear a fair amount about the hormone-disrupting chemical bisphenol-A (BPA) in can linings, what are other issues with food packaging the general public should be aware of?

Linings protect the cans from corrosion and the can’s content from contamination with dissolved metals. During the last years companies started to replace BPA linings and now label their cans as BPA-free. The consumer is usually not informed about the new material that is used instead. Alternative linings can be based on compounds very similar to BPA such as bisphenol F (BPF) and bisphenol S (BPS). Unfortunately, these chemicals substituting BPA have similar toxicological properties. In general, it would be desirable to have an open discussion on the safety of alternatives instead of simply stating that one chemical of concern was removed from the packaging.

Another issue I would like to refer to is recycling of food packaging materials. Although recycling reduces the amount of waste and saves resources, it can introduce unwanted chemicals into our packaging. In 2023, researchers found polybrominated flame retardants in black plastic items used for food packaging. These persistent and bioaccumulative flame retardants probably originated from waste electric and electronic equipment that was illegally fed into the recycling streams. A second example refers to the high concentrations of mineral oils in recycled paper and board, which are usually not removed during recycling processes. Mineral oils easily migrate from such packaging materials into the food. One solution, which would fail at the aspect of sustainability, could be the use of only fresh fiberboard for the production of food packaging. Further solutions could be the introduction of barriers that prevent migration of mineral oils or the use of alternative printing inks.

4. What should be done to improve the safety of food packaging?

Gaps exist in the legislation for food packaging worldwide, which should be filled. Scientists identified new challenges in toxicological research during the last years, which are currently not sufficiently considered during chemical risk assessment. These tasks include, e.g., endocrine disrupting chemicals, critical periods of development and mixture toxicity. At first, endocrine disrupting chemicals may interfere with the hormone system and cause a variety of severe diseases, but they are not routinely assessed. Many endocrine disrupting chemicals are known to be used in the production of food contact materials and may migrate into the food. Secondly, especially unborn children or infants may be easily harmed by chemicals during these critical periods of development. Thirdly, classical risk assessment of chemicals usually looks at only one chemical at a time. This does not reflect reality, because we are steadily exposed to highly complex mixtures of chemicals. It is very difficult to judge, whether these chemicals interfere with each other or if they act just on their own. Although these three developments in toxicology have not been included in the standard risk assessment of food contact materials so far, the awareness towards these issues is steadily growing.

5. What can parents do to safeguard their kids against potentially harmful substances in food packaging? Heat is known to increase migration of chemicals into food, so not microwaving in plastic is a good tip for families. But what about cold? Are frozen foods that come in plastic bags safe from the chemicals in that plastic?

It is true that the migration rate of chemicals from the packaging into the food is increased at hot temperatures. This also means that the chemical migration rate is decreased during the storage period in the freezer. However, we have to consider that the food may have been filled into its packaging when it was still hot or that it was even heated in the packaging before freezing. Further, the packaging of the frozen food may also be recommended for heating in the microwave or oven. Under these conditions, the alleged advantage of reduced chemical migration during freezing might be easily neutralized.

Parents may prepare meals with fresh and unprocessed products. When buying packaged food, they also may have a look at the packaging size: instead of buying four or six little portions of a certain food (e.g. yogurt), it may make sense to buy one big portion. This will reduce the surface-to-volume ratio, which is directly linked to the total amount of chemical migration. And of course it will also reduce the amount of waste.



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