Plastics
Last updated
Last updated
Plastics are lightweight, versatile, and cost-effective materials predominantly made from fossil carbon, though renewable sources are becoming more common. Since the 1950s, plastics have been widely used in food packaging, such as bottles, cups, trays, and bags.
Conventional plastics are made from fossil fuels, and their production contributes to climate change and air pollution. Certain plastics can be produced with a fraction of recycled material. However, to compensate for the degradation of polymer chains and subsequent loss of mechanical properties after use and recycling, the addition of virgin material is generally required.
Besides contributing to climate change, plastics can pollute the natural environment. When leakage happens at different life cycle stages, plastics end up in the environment (see Plastic Pollution). Since plastics are durable materials, they remain in the environment for decades (or centuries), releasing chemicals and degrading into smaller microplastics.
Plastics are chemically complex materials. They are made of polymers and oligomers, often include various additives that enhance their properties, and contain many non-intentionally added substances (NIAS) such as impurities from manufacturing, use, and recycling. These chemicals can transfer into food, a process known as chemical migration, which can pose health risks for consumers. Additionally, plastics can release microplastics during their lifecycle, leading to both environmental and potential human health concerns.
The end-of-life of plastic food packaging is challenging. While plastic recycling is one approach to reducing environmental impact, it is limited by technical (material properties, contamination risks, and the need for safety in food contact materials) as well as economic reasons. Mechanical recycling, which involves cleaning and reprocessing plastics, often results in lower-quality material that requires additives. Chemical recycling is an emerging alternative, but it can be limited to certain plastic types, be energy-intensive, and generate toxic waste. Further, chemical recycling approaches have not yet been proven to be sufficiently scalable. Despite these efforts, most plastic food packaging is either downcycled or not recycled at all, with PET bottles being a notable exception. Plastics that are not recovered for reuse or recycling are incinerated (waste to energy), landfilled, or littered.
If you want to learn more about plastics, you can explore the external resources linked below.