The Potential Harmful Effects of Food Packaging

Overview

• Food packaging contains a large number of chemical compounds that come into contact with food.
• Studies indicate that thousands of these chemicals can migrate into food, potentially causing harmful toxic effects, including endocrine disruption.
• Ultra-processed foods appear especially vulnerable to this contamination due to prolonged contact with packaging materials.

Modern food systems have made it possible to produce large quantities of food that is often affordable and widely accessible around the world. This success relies heavily on advances in modern chemistry:

• On one hand, synthetic nitrogen fertilizers and pesticides have significantly boosted agricultural yields.
• On the other, food preservation has greatly improved thanks to food additives and packaging materials (plastic, metal, silicone, paper, cardboard, etc.) that protect against microbial contamination and allow food to be transported over long distances.

However, this industrialization of the food supply chain comes with serious environmental consequences. Beyond its contribution to greenhouse gas emissions (especially from livestock) and soil and air pollution (see our article on this topic), the extensive use of chemical compounds in food production greatly increases the risk of food contamination. Consumers—including children—can thus be exposed to numerous synthetic molecules with known toxic effects, particularly pesticides, per- and polyfluoroalkyl substances (PFAS), phthalates, and microplastics.

Chemical Packaging

One significant yet relatively unknown source of contamination originates from chemicals that come directly into contact with food—referred to as food contact chemicals (FCCs). FCCs are used at various stages of food production (e.g. in equipment for processing, storage, and transport), but the chemicals in packaging materials have received the most attention in recent years.

A recent review of studies on the subject highlights the extent of this contamination. Analyses show that over 12,000 different chemical compounds are intentionally used in the manufacturing of food contact materials, and at least 2,800 of them are known to migrate into food. Experts believe the real contamination potential is much higher, estimating that due to impurities, cross-reactions, and degradation by-products, more than 100,000 distinct compounds may be unintentionally formed during manufacturing (see Figure 1).

In many cases, the identity and quantity of these chemicals are unknown, which means their presence in food could evade toxicological testing and go undetected by safety assessments.

When it comes to assessing the risks of FCCs, we are currently significantly behind. Unlike for the approximately 1,000 pesticides that can potentially contaminate food and are routinely monitored (ensuring their levels remain below toxic thresholds), there are no standardized analytical methods targeting many known FCCs—let alone those formed unintentionally during packaging production, whose identity is often unknown. This gap is particularly concerning given that the amount of FCCs in food is estimated to be at least 100 times higher than that of pesticides.

Two additional concerns cast doubt on our current approach to evaluating FCC toxicity:

1. Risk assessments often focus solely on genotoxicity (cancer-causing potential), even though many FCCs are now known to cause non-cancer-related effects, such as endocrine disruption (see next section).
2. Evaluations are typically conducted on individual chemicals, whereas most food packaging materials can release mixtures containing dozens to thousands of FCCs simultaneously into food. Even if each compound is present at a non-toxic level, research shows that “mixture effects” (the combined impact of multiple contaminants) can still pose significant risks (Figure 2).

In conclusion, it is likely that we are seriously underestimating both the extent of food contamination by food contact chemicals and the associated health risks.
This regulatory blind spot is especially worrisome when it comes to plastics, one of the main sources of potentially toxic compounds in everyday food packaging.

Plastics and Plasticizers

Plastics have become indispensable in the manufacture of everyday items. By 2050, global plastic production could reach one billion tonnes annually, nearly 1,000 times more than a century ago. Despite their usefulness, plastics have a major drawback: they accumulate in the environment. Since 1950, an estimated 7 billion tonnes of plastic waste have been generated. The fragmentation and erosion of this waste create tiny particles known as microplastics (less than 5 mm in diameter) and nanoplastics (less than 1 µm). These particles can enter the human body and may contribute to disease development. Recent studies have linked their presence to an increased risk of cardiovascular events and Alzheimer’s disease.

Crucially, this contamination doesn’t occur only through environmental degradation. Normal use of plastic materials in contact with food or beverages can also lead to the migration of micro- and nanoplastics into what we eat.

Bisphenols and Phthalates: Known Threats

Among FCCs, bisphenols and phthalates are among the best-studied. These plasticizers modify the properties of plastics—phthalates make plastics like polystyrene more flexible, while bisphenols contribute rigidity to polycarbonates and epoxy resins.

Both are known endocrine disruptors (EDCs), meaning they interfere with hormone-regulated physiological processes such as development, metabolism, and reproduction.

Documented health impacts include:

• Bisphenol A (BPA):
  • Reduced anoclitoral distance in infants
  • Type 2 diabetes (T2D) in adults
  • Insulin resistance in both children and adults
  • Polycystic ovary syndrome (PCOS)
  • Obesity and hypertension in children and adults
  • Cardiovascular disease (CVD)
• Phthalates:
  • Miscarriages
  • Shorter anogenital distance in boys
  • Insulin resistance
  • Early puberty in girls
  • Poor semen quality
  • Cognitive developmental issues
  • Reduced IQ

Canada is much more lenient than Europe regarding phthalate use in packaging and cosmetics. As a result, virtually all Canadians aged 6 to 79 have detectable levels of phthalates in their urine.

Although urinary BPA levels have decreased by about 50% between 2007 and 2019, BPA has largely been replaced by similar compounds like BPS and BPF. Studies suggest that BPS can also migrate into food and may have endocrine-disrupting effects similar to BPA.

FCCs and Ultra-Processed Foods

In recent years, numerous studies have linked ultra-processed food (UPF) consumption to obesity, cardiometabolic diseases, mental health disorders, and premature death. These effects are partially due to:

• Increased caloric intake and weight gain
• Additives like emulsifiers that promote chronic inflammation

A shared characteristic of UPFs is that they are prepackaged, often for long periods. Food may remain in contact with packaging for weeks, months, or even years, increasing contamination risk.

Worse, many items—like microwaveable meals in plastic trays—are heated in their packaging, which accelerates FCC migration into the food (according to the Arrhenius law, which links temperature to reaction speed).

Studies have shown that greater UPF consumption correlates with higher urinary levels of FCCs, such as phthalates and bisphenols. Additionally, the health risks associated with UPFs, such as obesity and cardiometabolic diseases, overlap with those caused by chronic exposure to FCCs like DEHP (a common phthalate) and BPA. Also concerning is the presence of PFAS (per- and polyfluoroalkyl substances) in fast-food packaging since these can migrate into greasy or salty foods and are well-documented endocrine disruptors. It is therefore possible that the migration of all of these compounds into ultra-processed foods could contribute to their negative impacts on health.

How to Reduce Exposure to FCCs

There are at least two concrete steps that can help reduce the ingestion of potentially toxic chemicals from food packaging:

1. Avoid heating food in plastic containers.
   Use alternatives like glass. Also, choose wood or metal utensils instead of plastic ones, which may contain brominated flame retardants from recycled plastics.
2. Minimize consumption of ultra-processed foods.
   These foods not only contain higher levels of FCCs but are also:
   • Nutritionally poor (high in calories, sugar, fat, and salt)
   • Low in essential nutrients (vitamins, minerals, and fibre)
   • Likely to replace healthier, less-processed options that protect against chronic diseases

In summary, the hidden chemicals in food packaging—especially plastics—pose underestimated health risks, particularly in ultra-processed foods. Reducing exposure through smarter choices and less packaging is a practical step toward better health.