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Spotlighting the hidden chemicals in processing equipment

Food companies have been warned not to “overlook” processing equipment as a path for chemicals to contaminate foods.

The extreme physical conditions applied during some processing steps and the prolonged contact with highly chemically complex, non-inert equipment typical for many modern food products can increase chemical migration, the Food Packaging Forum (FPF) has warned.

Companies producing ultra-processed foods (UPFs) should be particularly wary, the non-profit foundation noted in an update.

“While many food brands publicise improvements in the chemical safety of their packaging, fewer make commitments related to processing equipment,” FPF data scientist Lindsey Parkinson explained.

Scrutiny of chemicals from processing equipment

Food processing equipment is used to turn raw ingredients into finished food products, through cleaning, size reduction, separation, mixing, texturing, heating/cooling, shaping, and, finally, preserving and packaging.

Ingredients processing, for example, involves cereal grain milling, oilseed crushing and refining, and “fractionation and isolation”, through which specific components like proteins or starches are separated.

Many UPFs also undergo numerous stages (grinding, extrusion, high shear mixing, hot fill) and spend longer in contact with machinery. These conditions of high temperature, shear, and large surface area contact, in conjunction with often fatty foods, “can increase the likelihood and extent of equipment-related chemical migration”.

Research led by the University of Antwerp carried out last year found that highly processed plant-based proteins have higher levels of chemical contaminants than their animal-based counterparts, but concluded that there is no suggestion of “immediate risk” to consumers.

Parkinson noted that companies and consumers alike are more tuned in to migration of chemicals from food contact materials (FCMs). Various governments are also considering tighter regulations to restrict more chemicals and reduce contamination as pressure from campaigners intensifies.

However, the equipment surfaces to which foods are exposed are “equally extensive” to those for packaging, with several routes for chemicals to migrate into foods. This includes leaching metals, diffusion of plasticisers and lubricants, sanitiser carry-over, and abrasion-derived microplastics.

Repeated steam sterilisation can also break down silicone seals, releasing siloxanes, while high-energy UV or oxidising agents can degrade polytetrafluoroethylene (PTFE) coatings, producing perfluoroalkyl acids (PFAAs), which are a type of PFAS.

Both known hazardous chemicals and unknown or untested ones can pass from equipment to foods, explained Parkinson. Brands, therefore, risk reputational damage and costly recalls.

Compared to packaging, this area has historically received less attention, but scrutiny and data on real-world contributions are “steadily increasing”, she added.

Chemical fix is often not quick

In December, research was published showing that toxic chemicals in the food system are driving nearly $3 trillion a year in avoidable global health and environmental costs.

“Industrial chemicals are regulated far less stringently than pharmaceuticals but are present at every stage of the food chain. They are intentionally used in fertilisers and pesticides, in food processing equipment, and in packaging and coatings,” the report, by systems change advisory Systemiq and funded by the Grantham Foundation for the Protection of the Environment, noted.

The report highlighted concerns relating to bisphenols, like BPA, which is polymerised to produce polycarbonate plastics (used in bottles and foodware, including those intended for reuse, as well as equipment parts), and epoxy resins (used as protective linings for metal food cans, closures, and food processing equipment).

In some cases, there is no simple quick fix, or BPA alternative.

“Technical challenges persist in certain high-performance uses, such as heavy-duty corrosion protection and large-scale processing equipment, where alternatives carry higher costs or involve performance trade-offs,” the authors wrote.

“Some specialist applications, like polysulfide filtration membranes in dairy production, still lack viable substitutes and have been granted derogations (time-limited exceptions).”

PFAS, or so-called “forever chemicals”, have been at the centre of concerns. Shifting to PFAS-free alternatives often requires upfront investments in new processes and equipment – costs which are “difficult to justify” without supportive policies or clear regulatory deadlines, particularly for companies operating on thin margins, the Systemiq team noted.