Recycled and reused food contact plastics are ‘vectors’ for toxins – study

Research provides a unique review of contact chemicals in packaging, utensils, plates, etc and how they contaminate food

New research finds that recycled and reused food-contact plastics are “vectors for spreading chemicals of concern” because they accumulate and release hundreds of dangerous toxins, such as styrene, benzene, bisphenol, heavy metals, formaldehyde, and phthalates.

The study assessed hundreds of scientific publications on plastic and recycled plastic to provide a first-of-its-kind systematic review of food-contact chemicals in food packaging, utensils, plates, and other items and what is known about how the substances contaminate food.

“Hazardous chemicals can accumulate in recycled material and then migrate into foodstuffs, leading to chronic human exposure,” the authors wrote, noting bottles made from polyethene terephthalate (PET) plastic as a typical example.

The study comes amid a debate over how to reduce the amount of plastic waste filling the globe. The petrochemical industry, some governments, and many environmental groups have pushed for improvements to plastic's recyclability.

Though some types of material can be recycled, most cannot, and the study highlights how improving the recyclability of the material comes with risks: It identified 853 chemicals used in PET recycled plastic, and many of those have been discovered during the last two years.

Antimony and acetaldehyde were most commonly detected, while potent toxins like 2,4-DTBP, ethylene glycol, lead, terephthalic acid, bisphenol and cyclic PET oligomers were also most frequently found.

Moreover, the chemistry of plastics can be something like a black box. In the US, there’s very little regulation around what goes into the material, and the EU only requires light testing to determine which chemicals are in plastic.

The study characterizes plastics as “very complex materials containing hundreds of different, synthetic compounds which are more often than not poorly characterized for their hazard properties.” The analysis notes that some chemicals found in recycled plastics cannot be identified, adding to the risk of repeated recycling and accumulation.

“It’s not safe, and as the quality of recycled plastic decreases, the amount of potential contaminants goes up,” said Birgit Geueke, the study’s lead author and senior scientific officer with the Zurich-based Food Packaging Forum.

The data indicates chemicals are added or created during the recycling process. While 461 volatile organic compounds (VOCs) were detected in virgin plastic, some 573 were found in recycled material. Geueke said it was challenging to say why that occurred. Still, it could stem from the addition of chemicals during the recycling process, the addition of chemicals from the contaminated recycling stream, reactions among chemicals, or from plastic taking up additional chemicals when used the first time.

The review also highlighted widespread “illicit” recycling, in which the industry uses non-food-grade plastic made with flame retardants and other toxic compounds in recycled food packaging. Despite strict regulations on which types of plastic can be used for food contact, studies identified recycled electronics in the US, South Korea, and European markets.

“There are clear indications of brominated flame retardants that came from your old TV, computer, keyboard,” Geueke said. “It’s certainly not legal.”

The review identified similar problems with reusable plastic items that come into contact with food, such as kitchen utensils, water bottles, tableware, baby bottles, water dispensers, tubing for milking machines, and more.

Food from plastic’s first use or detergents used to clean the material can be absorbed and cause chemical changes and contamination in reused material, such as heating it or otherwise using it in a way it is not designed to be.

Consumers can protect themselves by avoiding plastic as much as possible, bringing non-plastic carryout packages to restaurants and moving food products from plastic packaging to containers made of safer materials.

But, ultimately, the most effective remedy is the elimination of plastic and the societal use of safer materials, the study’s authors wrote.

“A shift towards materials that can be safely reused due to their favourable, inert material properties could be a promising option to reduce the impacts of single-use food packaging on the environment and migrating chemicals on human health,” the paper states.