Tackling the toxics in plastics packaging

Abstract

The widespread use of plastic packaging for storing, transporting, and conveniently preparing or serving foodstuffs is significantly contributing to the global plastic pollution crisis. This has led to many efforts directed toward amending plastic packaging's end of life, such as recycling, or alternative material approaches, like increasingly using paper for food packaging. But these approaches often neglect the critical issue of chemical migration: When contacting foodstuffs, chemicals that are present in packaging transfer into food and thus unwittingly become part of the human diet. Hazardous chemicals, such as endocrine disrupters, carcinogens, or substances that bioaccumulate, are collectively referred to as "chemicals of concern." They can transfer from plastic packaging into food, together with other unknown or toxicologically uncharacterized chemicals. This chemical transfer is scientifically undisputed and makes plastic packaging a known, and avoidable, source of human exposure to synthetic, hazardous, and untested chemicals. Here, I discuss this issue and highlight aspects in need of improvement, namely the way that chemicals present in food packaging are assessed for toxicity. Further, I provide an outlook on how chemical contamination from food packaging could be addressed in the future. Robust innovations must attempt systemic change and tackle the issue of plastic pollution and chemical migration in a way that integrates all existing knowledge.

Fig 1. Schematic illustration of chemical migration from plastic food packaging into food.

Small molecules that are present in the plastic packaging item (red dots) can transfer out of the plastic into the food. The same is true for small molecules present in the food (yellow dot), a process known as flavor scalping. Also, environmental contaminants (blue dots) can be absorbed in the plastic packaging and subsequently be released again, making this an issue for plastics recycling. Chemical migration, flavor scalping, and absorption depend on temperature, time, and the chemical properties of the packaging, the food and the chemicals that are transferring from one medium to another. Created with BioRender.com.

Fig 2. Chemical migration from packaging into food—the status quo.

Chemicals migrate from plastic packaging into food, and some of the migrating chemicals are known to be hazardous. Chronic exposure to certain hazardous chemicals is associated with avoidable chronic disease. This means that reducing exposure to hazardous chemicals from plastic food packaging contributes to disease prevention. Unknown or untested chemicals that migrate into food must also be addressed, as they may include hazardous chemicals.

Fig 3

The 3 key areas for improving the chemical safety of food packaging, based on current knowledge: (A) expanding hazard assessment to include other relevant toxicities; (B) systematically assessing migrating chemicals for their ability to disrupt the endocrine system by using appropriate testing that allow for identification of non-monotonic dose responses; (C) tackling mixture toxicity to identify toxic effects of all chemicals migrating simultaneously.

Fig 4. Schematic overview of the human and environmental health impacts of the plastics life cycle.

Adapted and reprinted with permission from the Health and Environment Alliance [67].

Fig 5. Robustly improving food packaging requires consideration of numerous aspects to achieve systemic change that does not result in the creation of new wicked problems.