Plastic Leakage and Marine Litter: Why Your Packaging LCA Needs These Indicators
Most packaging LCAs tell you about climate change, water use, and resource depletion. They don't tell you what happens when that packaging escapes the waste system entirely.
That's a significant blind spot. UNEP estimates 19–23 million tonnes of plastic waste leak into aquatic ecosystems every year. Until recently, LCA had no robust way to capture this. The data wasn't there — leakage rates were unknown, environmental fate was poorly mapped, and ecosystem impact research was still emerging.
That's now changing.
What's new: the MariLCA microplastics method
The Marine Impacts in Life Cycle Assessment (MariLCA) working group released characterisation factors in 2025 that quantify ecological impacts of plastic leakage into aquatic environments. Impacts are expressed as Potentially Disappeared Fraction (PDF) of species — the same unit used in ecotoxicity modelling — making them directly comparable with established LCA indicators.
Here's what matters for packaging decisions:
The factors capture physical harm, not chemical toxicity. Current characterisation factors address ingestion and entanglement impacts on aquatic species. Chemical toxicity and human health effects remain under development.
Fate drives the result as much as material choice. Denser polymers like PET, PVC, and PLA sediment quickly and have lower exposure in the water column. Lighter materials — EPS, polypropylene — stay mobile longer, producing higher impact factors.
Polymer type, particle size, and shape all matter. The characterisation factors vary significantly across these parameters, enabling genuine differentiation between packaging formats.
The scale of impact is material. Initial assessments show marine microplastic impacts sitting at a similar order of magnitude to climate change, ecotoxicity, eutrophication, and other established ecosystem quality indicators. This isn't a rounding error — it belongs in the assessment.
Where the uncertainties sit
The science is advancing faster than the inventory data. Leakage fractions are often assumed at around 1% in the absence of better figures. Selecting the right elementary flows — polymer type, size fraction — still requires judgement. And guidance on terrestrial-to-marine transfer pathways remains limited. These indicators are best suited to screening assessments and comparative decision support, not precise marketing claims.
Regulatory momentum is building
In Australia, APCO is placing greater emphasis on packaging outcomes beyond recyclability, including leakage risk. In Europe, the PPWR is tightening scrutiny on packaging design and environmental claims. And in the United States, Oregon's EPR scheme explicitly references marine microplastic litter and plastic leakage alongside LCA calculations.
The direction is clear: comprehensive impact accounting is where packaging regulation is heading.
PIQET now includes plastic leakage indicators
We've integrated two new indicators into PIQET to put this into practice:
Marine Microplastic — translates plastic emissions into ecological effect metrics based on plastic type, size, and fate pathways using the MariLCA characterisation factors.
Plastic Leakage Inventory — quantifies plastic leaving the circular economy into the environment, reporting leakage rates by compartment (soil, river, ocean) using plastic flow analysis methods.
These sit alongside PIQET's existing climate, water, and resource indicators — giving you the full picture of your packaging's environmental performance.
The bottom line
If your packaging LCA doesn't account for what happens when materials escape the system, it's missing one of the most publicly visible and ecologically significant impacts of packaging waste. The methods now exist. The regulatory direction supports it. And PIQET makes it straightforward to include.
For more on incorporating plastic impact categories into your packaging assessments, contact PIQET Support.