Know your Scottish Salmon

Why are we still talking about Expanded Polystyrene (EPS) fish boxes

Autumn 2021 Fidra a report1 that explored alternative options to the extensively used expanded polystyrene (EPS) fish box which we shared across the industry, including with retailers. When we updated our UK retailer Scottish salmon farming transparency table we took the opportunity to check if our report, other research2 or other external influences were driving changes in the use expanded polystyrene (EPS) across retailers.

What is an Expanded Polystyrene fish box?

Expanded polystyrene and extruded polystyrene (XPS) boxes are the main materials used to transport fish products across the UK and most of the world3. They protect produce from both damage and temperature variation, they are cheap and lightweight therefore easier to transport. In theory they can be reused and easily recycled. The demand for fish products across Europe is increasing and many see EPS fish boxes as fundamental for meeting demand. However, in reality, EPS and XPS boxes are not reused or appropriately recycled, and incorrectly disposed of, the manufacturing and their use can all cause a significant impact on the environmental4,5.

Over a year ago Fidra, in collaboration with TAUW, shared findings on the available alternatives to using EPS in fish boxes – there is no law in place to mandate these changes, but has providing evidence helped?

All of the retailers* have made commitments to move away from single use plastics across their stores and throughout supply chains. Many are committing to more sustainable recyclable options. These commitments are slow and often not seen by consumers immediately due to prior contracts and research trials often required. Many retailers have trialled reuse/refill schemes in stores, which have had short-term success. Retailers trying to move towards having more loose products can have consequences of an increase in food waste. It is a difficult balancing act when working with the evolving consumer, the rise in inflation and an impending economic crash on the horizon. However, consumers don’t have any contact with fish boxes, this is where changes can and should be made by retailers, now.

Sainsbury’s have long used reusable bulk bins with their Scottish suppliers of farmed salmon, Mowi Scotland. To embed a system of reusable fish transportation boxes into their supply chains with their farmed Scottish salmon producer Scottish Sea Farms, M&S have trialled FishCaps  for seafood products. FishCaps are made by FoodCap International, a brand trying to replace single use polystyrene fish boxes with a multi-reuse packaging6. M&S anticipate the outcome of this trail to be openly available via their corporate website in 2023.

Over the last year Asda has been looking at ways to decrease their EPS use, with the main drivers coming from their own in-house environmental targets and consumer demand. They are working with suppliers to decrease EPS use and all hard plastic. They, like other retailers are attempting to identify the trade-offs involved in reducing plastic (e.g. phasing out plastic but raising carbon footprint).

Co-op have been actively focused on moving away from the use of EPS fish boxes across the company, they are working with a variety of suppliers who are making changes to their seafood boxes. Several of their suppliers have moved away from single-use EPS packaging and onto bulk plastic insulated returnable bins which are washed and reused for seafood produce. They are also involved in an ongoing project looking at using 25kg EPP (expanded polypropylene) boxes, which would be recycled much the same as the bulk bins through the supply chain. In addition to this Co-op are committed to a project focused on the use of cardboard boxes instead of EPS.

Meanwhile Tesco, as the largest supermarket chain, would hope in order to see real improvement in sustainable packaging across the sector, seafood products packaging such as Scottish salmon should be standardised. Tesco do not stock a large proportion of Scottish salmon.

What next?

The FAO assessed sustainability of agricultural plastics in a 2021 report and highlighted that EPS fish boxes received a high relative risk score and ranked within the five most likely plastics to have harmful consequences on the environment7. The evidence of the environmental impacts of EPS fish boxes being incorrectly disposed of is mounting4,5,7, consumers are conscientious and more aware of the plastic waste issue, and retailers recognise the plastic-free movement isn’t going away anytime soon. The salmon farming industry was dependant on the use of EPS fish boxes due to their ease and ignored the negative impacts these boxes have on the planet – but have the tides turned quickly enough? We now know immediate action is required – EPS is not a long-term option. Read more about the alternatives here.

Salmon in a polystyrene fish box ©Fidra
Polystyrene fish box waste © Fidra

*Retailers who engaged with Fidra


[1] TAUW. Assessment of Alternative for EPS Fish Boxes.; 2021. Accessed March 16, 2022.

[2] Hansen AÅ, Rødbotten M, Lea P, Rotabakk BT, Birkeland S, Pettersen MK. Effect of Transport Packaging and Repackaging into Modified Atmosphere on Shelf Life and Quality of Thawed Atlantic Cod Loins. Packaging Technology and Science. 2015;28(11):925-938. doi:10.1002/pts.2139

[3] British Plastics Federation EPS Group. From Port to Plate.; 2020. Accessed December 16, 2022. ayinthelifeofafishbox/index.html+&cd=3&hl=en&ct=clnk&gl=uk.

[4] Turner A. Foamed Polystyrene in the Marine Environment: Sources, Additives, Transport, Behavior, and Impacts. Environ Sci Technol. 2020;54(17):10411-10420. doi:10.1021/acs.est.0c03221

[5] Fauna & Flora International. Breaking down Ocean Polystyrene – An Initial Investigation into Marine Uses of Foamed Polystyrene.; 2020. Accessed December 19, 2022.

[6] FoodCap International. FishCap – Turning the tide on single-use seafood packaging. Accessed November 16, 2022.

[7] FAO. Assessment of Agricultural Plastics and Their Sustainability: A Call for Action. FAO; 2021. doi:10.4060/cb7856en

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