Environmental credentials
At every stage, from manufacture to disposal, EPS fish boxes offers outstanding environmental credentials. In fact the impacts of using EPS in critical fish box applications far outweigh the impacts and risks of food damage and wastage which would otherwise occur – for example when more energy might be needed for cooling less thermally-efficient packs.
The styrene base for EPS is itself a by-product of oil refining but it is reassuring to know that styrene also occurs throughout the natural world – in strawberries, coffee beans, wine and beer. The styrene is blown into expanded polystyrene using a non-CFC gas called pentane which is quickly broken down during production into carbon dioxide and water. Pentane has low volatility and is found in the digestive systems of animals and created when vegetable matter decomposes in a process called anaerobic composting.
Put simply, EPS is 98% air and 2% plastic. It uses a polymer called styrene monomer as its base material. The monomer is a by-product of petroleum and naphtha produced during oil refining which provides a ready and continuous source. Styrene also occurs naturally in many foods such as strawberries, coffee beans, beer and wine.
A gas called pentane is used as a non-CFC expansion agent to blow the styrene into its final lightweight, expanded cellular form. During the production process, the styrene monomer is effectively eliminated during its polymerisation and the pentane is quickly broken down into carbon dioxide and water. Pentane has low volatility – for example, it is found in the digestive systems of animals and created when vegetable matter decomposes in a process called anaerobic composting.
On the basis of current EU testing and classification regimes, styrene monomer is non-toxic in all normal usage and is not classified in terms of carcinogenicity or mutagenicity. Pentane has no potential to harm the ozone layer with CFCs or HCFCs.
EPS has been made for more than half a century and EPS manufacturers comply with all current regulatory and legislative requirements. The processes include a combination of heat and pressure utilising clean technologies and minimising energy inputs and water usage through closed loop energy recycling. For all of these reasons, EPS manufacture is a highly efficient process.
No solid waste is created and process waste and off-cuts are reintroduced to the production batch immediately. Atmospheric and land/water emissions are strictly controlled resulting in no significant localised impacts.
Due to the light weight of EPS and its relatively high volume, the EPS industry has grown to be located close to its home markets. This means that, in the UK, a number of strategic production sites enable the seafood and fish supply chain industry to have a constant, close supply of EPS fish boxes to meet their continuous demands.
This also means that users of EPS fish boxes can be reassured that all EPS is supplied to exacting standards from a trusted supplier.
A recent (2011) in-depth Life Cycle Analysis has been prepared by PWC Ecobilan in France. It compared the Life Cycle Performance of three fish box materials – EPS, corrugated polypropylene and water-resistant cardboard for fresh fish packaging using real market movements covering the French, Spanish and Danish sectors.
This was a cradle-to-grave study. In the first sensitivity analysis covering energy and waste management – the materials all gave ‘balanced results’. In two other sensitivity analyses covering recycling, the EPS fish boxes give better results than polypropylene and cardboard except in one area – the production of photochemical oxidants from the use of pentane as a blowing agent. This confirms that, in spite of other fish box materials being available, there are no overall better options and the market leading position of EPS fish boxes is justified.
British Plastics Federation