This one study is conducting a comprehensive life cycle assessment (LCA) of polyethylene (PE) packaging and its alternatives (paper, glass, aluminum, and steel) in the United States. The goal is to provide a comprehensive understanding potential environmental impacts and trade-offs associated with PE and alternative materials. The study focuses on five main packaging applications:

• Cabinet foils
• Stretch films for pallet packaging
• Heavy Duty Bags (HDS)
• Bottles for non-food purposes
• Flexible food bags

The research compares PE and alternative packaging materials based on the following environmental impact categories: global warming potential (GWP), fossil energy use, mineral resource use, and water scarcity.

Weight and material composition data were obtained in 2023 from physical samples, specification sheets, and industry expertsAll formats contained a specific post-consumer recycled content (PCR) that represented the industry average for that material and format. Alternative packaging materials were selected and compared based on packaging capacity, with normalization equivalencies used for different sample capacities.

The study assesses potential environmental impacts from cradle to end-of-life (EoL), excluding the use phase, and identifies opportunities and potential trade-offs for PE-based packaging and alternative materials.

Methodology

EcoImpact-COMPASS™ software used. The platform has been critically reviewed by a third party and found to enable results and reporting in accordance with ISO 14040 and 14044 standards in May 2022. The software can be used to calculate potential life cycle environmental impacts broken down into raw material, manufacturing, transport and EoL stages.

Key impact indicators

The study uses median indicators to ensure clarity, robustness and avoid clustering:

1. Global Warming Potential (GWP): kg CO2 eq.
2. Use of fossil energy: Unit
3. Use of mineral resources: kg
4. Lack of water: liters of world eq.

Results and discussion

Most studies have found that PE packaging has a lower potential environmental impact than alternative materials. The light weight of PE materials compared to most alternatives contributed to these lower impacts. In cases where PE did not have the lowest impact, it was usually compared to lightweight paper alternatives that contained other materials, such as plastic or kaolin clay, to meet functional requirements.

PE packaging demonstrated a lower life cycle GWP than alternative materials in 16 of 19 comparisons. Material efficiencies drove the trends; in 18 of 19 comparisons, the material with the lowest weight had the lowest life cycle GWP. PE had the lowest weight requirements in 18 of 19 comparisons, with one multi-material paper packaging format weighing less than the comparable PE format. The remaining paper packaging formats required 1.4 to 11 times the weight of PE. Glass, aluminum, and steel formats required 3 to 48 times the weight of PE.

The study findings are intended to help stakeholders and policymakers make informed decisions that balance mitigating environmental impact with maintaining product functionality and achieving sustainability goals. Policies that favor specific packaging materials over others should be based on data, scientific methodologies, and consider the full life cycle and potential environmental impacts of these materials to avoid unintended consequences such as burden shifting. Spring

Glossary of key terms:

• LCA (Life Cycle Assessment): Assessment of the environmental impacts of a product or service throughout its life cycle, from raw material extraction to disposal or recycling.
• PE (Polyethylene): Polyethylene, a common plastic used to make packaging.
• GWP (Global Warming Potential): Global warming potential, a measure of how much a given gas contributes to climate warming compared to carbon dioxide (CO2).
• End of Life (EoL): End of product life includes processes such as recycling, incineration or landfilling.
• EPR (Extended Producer Responsibility): Extended producer responsibility, the principle according to which the manufacturer is responsible for the environmental impact of a product throughout its life cycle, including EoL.
• PCR (Post-Consumer Recycled): Recycled material that comes from waste that has already been used by consumers.
• Burden Shifting: Environmental burden shifting, when environmental impact is reduced in one stage of the life cycle but increased in another.
• Functional Unit: Functional unit, a defined quantity of a function for which an LCA study is being conducted (e.g. packaging for 1 kg of product).
• Midpoint Indicators: Life cycle indicators that describe environmental impact at the mid-level of the causal chain (e.g. GWP, water consumption).
• Endpoint Indicators: Life cycle indicators that describe the final impact on environmental components such as human health, ecosystems and resources.