Plastic packaging can have substantially smaller environmental impacts—including 70% lower greenhouse gas emissions—compared to other packaging materials, according to a new study.
The findings suggest that although there are major concerns about the short use span of single-use plastics and the consequences of improper disposal, in the big picture the strain they cause on the planet may be less than that of reasonable alternatives.
In the new study, researchers performed a life cycle analysis to compare the environmental impact of packaging made from polyethylene (PE) plastic to containers made from paper, glass, aluminum, and steel. Using standard life-cycle analysis software, they tracked the impacts from obtaining raw materials to manufacturing, transportation, distribution, and disposal.
Past life-cycle analysis studies have mostly focused on greenhouse gas emissions from plastics in general. This is the first to focus specifically on PE, the plastic type most commonly used for packaging. In addition, the researchers evaluated the impacts in terms of not just greenhouse gas emissions but also mineral resource use, fossil energy consumption, and water scarcity.
The research was funded by the petroleum giant ExxonMobil, and the research team includes several scientists employed by the company. (Most plastics are made from petroleum.) Yet the findings are in line with other studies that suggest that lightweight, durable plastics enable cheaper, more fuel-efficient transport of products across long distances and protect food and other good from spoilage, minimizing waste.
The researchers investigated the five main packaging types made from PE: collation shrink films, which hold together individual items sold as a set, such as a 6-pack of bottled water; stretch films for wrapping pallets; heavy duty sacks such as for cement or pet kibble; non-food bottles such as for shampoo; and flexible food pouches such as for beverages or spices. In all they evaluated 32 plastic and non-plastic products and made 19 comparisons of plastic to non-plastic packaging.
In 14 out of 19 comparisons, PE-based packaging used fewer fossil resources than other materials, the researchers report in the journal Science of the Total Environment. In 16 of 19 comparisons, PE was associated with lower greenhouse gas emissions, water scarcity impact, and mineral resource use.
For most packaging types, obtaining and processing raw materials represents the biggest contributor to overall life-cycle impacts. “The mass of packaging material required to meet the functional unit is a significant driver of the directional results,” the researchers write: in other words, plastic packaging is lightweight and uses relatively little material, so it usually comes out ahead.
The comparisons in which PE was bested by another packaging type typically involved lightweight packaging made of mixed materials, such as a paper sack with a plastic liner.
The picture is mostly similar if packaging is produced from recycled materials, the researchers found—although recycled plastic can require more material for structural integrity, which erodes its benefits.
The researchers also combined the results of their life-cycle analysis with data on market demand for different packaging types in the United States. This calculation revealed that substituting PE packaging for other materials could reduce greenhouse gas emissions from packaging by about 70%.
The findings can inform debates about regulating single-use plastics or implementing extended producer responsibility (EPR), which requires manufacturers to help cover the cost of recycling or disposing of their products, the researchers argue.
Source: Avery E. et al. “Polyethylene packaging and alternative materials in the United States: A life cycle assessment.” Science of the Total Environment 2025.
Image: Lisa Risager via Flickr.
