HDPE vs EPS in Seafood Packaging: A Comparative LCA

A detailed LCA uncovers the operational trade-offs between HDPE crates and lightweight EPS boxes in the cold chain supply.

Seafood distribution depends on reliable, hygienic, and thermally efficient packaging to preserve product quality through cold chain logistics. However, environmental concerns, particularly regarding marine litter and fossil resource depletion, are driving a reassessment of packaging strategies. A recent Life Cycle Assessment in Spain compares two standard distribution formats:

• Reusable HDPE crates (RPC)
• Single-use Expanded Polystyrene boxes (EPS)

The results offer insights into the trade-offs between durability, weight, transport emissions, and system design.

You can also read: LCA of Smart Labels – Insights for Intelligent Packaging.

Methodological Framework

The study applies a cradle-to-grave LCA approach, following ISO 14040 and ISO 14044 standards. Researchers modeled the environmental burdens of packaging used for the distribution of 1.26 million tonnes of fresh fish from the Port of Vigo to various markets across Spain. The analysis employed the Environmental Footprint 3.1 method and focused on six midpoint indicators: climate change, acidification, freshwater and marine eutrophication, fossil resource use, and water use.

Packaging comparison: RPCs vs. EPS boxes in seafood distribution impact. Courtesy of Exploring the environmental impacts of plastic packaging: A comprehensive life cycle analysis for seafood distribution crates.

The system boundaries encompassed raw material extraction, manufacturing, transportation, use-phase logistics (including cleaning for reusable crates), and end-of-life treatment. The team defined functional equivalence based on payload: each system’s capacity to transport a given mass of seafood and ice under cold chain conditions.

Packaging Design and Functional Parameters

EPS boxes, typically composed of 98% air, provide excellent thermal insulation and a low tare weight (0.203 kg per unit). Each box holds 6.4 kg of fish and 1.6 kg of ice. Manufacturers produce EPS by pre-expanding polystyrene beads and molding them through steam-assisted compression. This process consumes 0.11 kWh per unit and requires additional steam inputs.

In contrast, manufacturers produce reusable plastic crates by injection-molding virgin HDPE pellets, resulting in a final weight of 1.2 kg. They transport 10 kg of fish and 2 kg of ice, and follow a closed-loop system of reuse, cleaning, and redistribution. Each crate undergoes approximately 120 use cycles per year, with an expected lifespan of 10.5 years. Manufacturing requires 0.31 kWh per unit, plus masterbatch pigment additives (~2.4% by weight) compliant with EU food-contact regulations.

Schematic overview of the boundaries of the systems. Courtesy of Exploring the environmental impacts of plastic packaging: A comprehensive life cycle analysis for seafood distribution crates.

Logistics and Distribution Scenarios

The study evaluated three distribution routes: local (average 19.7 km), regional (94.4 km), and national (610 km). Suppliers pack EPS boxes in protective plastic bags for transport, while they stack RPCs on pallets (304 units per pallet, 33 pallets per truck). Refrigerated trucks carry filled containers, and RPCs require return logistics for cleaning and redistribution.

Workers wash RPCs either at the port or in centralized factory tunnels, depending on infrastructure. The process uses pressurized hot water (~55°C), detergent dosing, and wastewater treatment. Each wash cycle consumes 0.29 kWh per crate, 1.2 kg of water, and 1 g of detergent. In the base-case scenario, factories handle 20% of crate washing, while sensitivity analyses test fully port-based and fully factory-based washing strategies.

Life Cycle Inventory and Impact Modeling

Raw material sourcing included upstream processes such as naphtha cracking for HDPE and styrene polymerization for EPS, based on datasets from Ecoinvent v3.10. Transportation stages accounted for distances from polymer production sites (average 4000 km) to manufacturing plants in Galicia. Distribution phases included both filled container transport and empty crate backhauling. Energy mixes reflected the Spanish electricity grid for 2021.

The study modeled EPS end-of-life pathways through mechanical compaction and reuse in secondary products like furniture or molding foams.

For HDPE crates, it considered reprocessing into construction materials such as pipes. Using system expansion, researchers credited avoided impacts from virgin material substitution while acknowledging limitations from quality degradation and recycling losses.

Results and Interpretation

Climate change results for reusable plastic crates (RPC) and single-use EPS boxes for the different distribution scenarios assessed. Courtesy of Exploring the environmental impacts of plastic packaging: A comprehensive life cycle analysis for seafood distribution crates.

Across all three distribution scenarios, transportation of filled containers consistently dominated environmental impacts.

In the national route, the climate change impact reached 6.04×10⁸ kg CO₂ eq. for reusable HDPE crates and 5.39×10⁸ kg CO₂ eq. for EPS. This disparity stems from the weight difference: although RPCs offer higher payload capacity per unit, their greater tare weight increases emissions over longer distances.

For local distribution, RPCs showed slightly lower environmental impacts than EPS, particularly with port-based washing. While the mass-distance product favors lighter packaging for long-haul routes, optimized RPC systems with high rotation rates can offset these advantages through efficient washing and logistics.

Washing emerged as the second-highest contributor to the reusable HDPE crates footprint, accounting for up to 28% of total climate impact in the local scenario. Factory-based washing requires additional transport and energy, whereas port-based cleaning, already implemented in 80% of cases, significantly reduces overall burden. This logistical variable strongly influenced sensitivity results.

Recycling benefits also differed between systems. EPS boxes achieved higher avoided impacts per functional unit due to cleaner material recovery, lighter mass, and efficient compacting processes. While HDPE crate recycling avoids virgin resin production, the higher energy intensity and heavier mass reduce the relative gains.

Technical Implications

The study illustrates how environmental performance depends not only on material selection, but also on system design, supply chain integration, and operational parameters. Packaging engineers can significantly influence sustainability outcomes by adjusting crate geometry, wall thickness, and stackability to reduce tare weight without compromising structural integrity.

Potential improvements include the integration of recycled HDPE that complies with Regulation EU 10/2011 for food contact, redesign of RPCs to maximize fish-to-weight ratio, and deployment of on-site washing infrastructure at major ports to eliminate return trips. Additionally, incorporating RFID or QR-based tracking could enhance reuse system efficiency and minimize crate loss, currently estimated at 1%.

While EPS maintains an environmental advantage for long-distance seafood transport, RPCs better support circular economy principles and comply with EU policy directives, especially when operators maximize reuse rates and minimize washing energy.