Recyclable consumables

Six common plastic packaging and recycling myths

Image credit: Wrap

Increasing consumer awareness of plastic use and waste have forced brands, manufacturers and consumers to rethink the sustainability of their product packaging. We consider the facts - and not the myths - about the environmental credentials of potential replacements for plastics.

Myth 1: Biodegradable means compostable and therefore sustainable

Manufacturers of biodegradable and compostable packaging claim it is more sustainable and environmentally friendly than plastics because it is made from a renewable carbon source – plant-based materials, such as corn oil, starch, and plants – and because it will eventually break down in the environment.

According to the Bio-based and Biodegradable Industry Association, compostable bioplastics currently represent approximately 10,000 tonnes of UK sales. In 2018, global production capacities of bioplastics amounted to about 2.11 million tonnes (Mt), with almost 65 per cent (1.2Mt) of the volume destined for the packaging market – the biggest market segment within the bioplastics industry.

To describe a material as ‘compostable’, from a coffee cup to a drinks bottle, it must break down in under 12 weeks in composting conditions. Yet, in the UK, very little biodegradable and compostable packaging is industrially composted.

Richard Kirkman, chief technology and innovation officer at UK waste services provider Veolia UK, says the company can process only “very, very small amounts” of these materials and, in practice, they are currently only processing starch-based biodegradable food bags – those used for food waste collection bins – and some coffee cups. Most do not decompose in the necessary timescale while others get screened out at the sorting process, which isn’t always able to determine which are ‘good’ biodegradable items and which are ‘bad’.

Jarno Stet, waste services manager at Westminster City Council, says another organic composting technique, aerobic digestion, requires pulping waste into a slurry, and many biodegradable and compostable items do not pulp properly.

Therefore, most ‘compostable’ packaging in the UK is processed as general waste.

Plant-based polyethylene terephthalate (PET) can be recycled because the polymer is identical to fossil-fuel-based PET; however, many question the environmental benefits of using arable land to produce plastics.

European Bioplastics says a market of 2.62Mt would need only 1.02 million hectares, or around 0.02 per cent of the global agricultural area, to grow grain for packaging. However, this would barely make a dent in today’s volume of plastic use. According to a 2017-2018 report from PlasticsEurope, 8.4Mt of plastic were recycled in Europe in 2016.

Myth 2: Aluminium, glass and paper are lower-carbon alternatives to plastic  

Aluminium, glass and paper-based products are all instantly recognisable as recyclable and therefore considered more sustainable and environmentally friendly. Therefore, many brands have swapped plastic for these materials wherever possible to appeal to environmentally conscious consumers.

Yet research shows they produce more carbon than plastics. A 2011 peer-reviewed study by Denkstatt compared plastic-packaging polymers – LDPE, LLDPE, HDPE, PP, PVC, PS, EPS and PET – with tin-plate, steel, aluminium, glass, corrugated-board, cardboard, paper and fibre-cast, paper-based composites and wood. It found that if these materials were to replace plastics, the packaging mass would, on average, increase by a factor of 3.6, and life-cycle energy demand by a factor of 2.2, or 1,240 million gigajoules per year, which is equivalent to 20 million heated homes.

Among other things, plastic bottles take less space on trucks than glass bottles, and plastic food packaging contributes to a longer shelf life for fresh food. Polymers can usually do the same with significantly less material mass per unit.

In most cases, the report says, this leads to lower production energy and greenhouse gas emissions per functional unit. Among the seven plastic-packaging sectors, beverage bottles, shrink and stretch films and other flexible packaging show the highest overall benefit.

Similarly, it takes more than four times as much energy to manufacture a paper bag as a plastic bag, according to the Northern Ireland Assembly.

Paper bags, it says, generate 70 per cent more air and 50 times more water pollutants than plastic. In terms of reusability, a polymer-based bag can carry 2,500 times its own weight and stay strong when wet; it can be re-used many times, and is compact enough to be carried in a pocket or bag. Furthermore, it takes 91 per cent less energy to recycle a kilogram of plastic than a kilogram of paper.

Myth 3: All plastics are bad

Since the 1950s, plastic use has been increasing exponentially, largely because it is versatile, cost-effective and lightweight. According to the British Plastics Federation, 50 per cent of all products manufactured in Europe are packed in plastic, yet in terms of weight it accounts for only 17 per cent of total packaging materials used.

While undeniably over­exploited, some single-use plastics are vital, particularly in areas such as medicine. Multi-use polymers have their advantages too, notably their durability.

The most common use of plastic packaging is for keeping food fresh. According to the Waste and Resources Action Programme (WRAP), a staggering one-third of all food produced in the world is wasted; in the UK alone, £810 worth of food is thrown away each year by the average household. Without plastic packaging, these figures could increase even further.

Stephen Aldridge and Laurel Miller, authors of ‘Why Shrink-Wrap a Cucumber? The Complete Guide to Environmental Packaging’, say a wrapped cucumber lasts more than three times as long as an open one and will lose just 1.5 per cent of its weight through evaporation after 14 days, compared with 3.5 per cent in three days for an unwrapped cucumber.

A recent Daily Mail campaign to unshrink-wrap cucumbers led to the Co-op supermarket chain using a breathable liner inside the cardboard containers displaying the cucumbers. Despite claims that this would keep the produce fresh for 40 days, the cucumbers started deteriorating as soon as the containers were put on the shelf.  

Ostfold Research, a Norwegian public research organisation that studies the environmental performance of products and services, found that plastic baskets increased the shelf life of grapes and reduced waste between the farm and consumer by 75 per cent.

Myth 4: ‘Recyclable’ means widely recycled

Some paper and cardboard items are misleadingly believed to be recyclable and some are even labelled as such. Domino’s Pizza, for example, delivers more than two million pizzas a day worldwide, and its pizza boxes are labelled ‘100 per cent recyclable’. In theory, being made of cardboard (80 per cent recycled and the remaining 20 per cent Forest Stewardship Council-certified), they could be. However, any material soiled with food waste, especially grease, is deemed not recyclable.

“If something is contaminated or made wet or greasy, it is not recyclable; the grease and liquids deteriorate the structures of the fibres of paper packaging, and during the few days it takes to get to the paper mill, it will rot and have very short fibre lengths, making it hard to recycle,” explains Veolia’s Kirkman.

If the pizza box has a liner, and none of the food has spilt onto the box, it can be recycled.

Sandwich boxes are mostly made not from plastic but from cardboard, which consumers often assume can be recycled too. Marks & Spencer and Greggs, for example, label their boxes as ‘widely recycled’ or they feature the universal recycling symbol.

Like pizza boxes, they can only be recycled if unspoiled by food, and if the plastic window has been removed. Many are also lined with plastic, like coffee cups, making them even harder to recycle. Those boxes are significant contributors to waste. Pret a Manger alone sells 1.55 million sandwiches a week in the UK.

When asked if plastic containers would be a better alternative, Jarno Stet of Westminster Council says: “Packaging in PET or HDPE (high-denstity polyethylene), depending on design, might provide a better market for recycling. A preferable solution, however, is to encourage food consumption onsite, so it doesn’t require packaging at all.”

Myth 5: Material is more important than design

Often, when it comes to the sustainability of packaging, material is given more consideration than a product’s design. Yet design can have a huge impact on the reusability and recyclability of packaging. Design often determines the ways the packaging is used and/or discarded .

“PET or HDPE plastic bottles are easy to recycle, but can be more difficult if the information sleeve is a different polymer,” says Kirkman. “Black plastic, often used for food containers because it hides food spills better, cannot be easily scanned and sorted for recycling, whereas white could lead to increased recycling.”

Designing for practical use – rather than purely marketing purposes – is also important. The amount of packaging can be reduced by providing QR codes for customers to access product information, or by using stackable square bottles to minimise space during shipping.

Kirkman recommends simple adjustments to packaging design to increase recyclability, such as lids made with the same plastic as the bottle, so they can be recycled together, a ‘traffic light’ sign on packaging for consumers to understand how to recycle it better, and a tax that penalises manufacturers not incorporating recycled content in their products to encourage a circular economy.

Simplified and clearly labelled packaging can have a huge impact on reducing waste and emissions. According to a WRAP report, it is estimated that 1.2kg of HDPE waste saves the production of 1kg virgin HDPE. For PET recycling, 1.3kg of waste PET saves 1kg of virgin PET.

Myth 6: Plastic has no value

“Plastic is a good material: the problem is how it is designed and discarded,” says Professor Richard Thompson of Plymouth University’s School of Biological and Marine Services.

Thompson highlights a key problem with plastic: the material is deemed as inherently disposable and hence having no value. Every year about 26 million tonnes of plastic waste is generated in the EU and less than 30 per cent of it is recycled – not because it can’t be, but because it is simply thrown away.

In the recycling chain, plastic bottles are the most abundant and valuable, yet only around 60 per cent are captured: consumers are throwing 40 per cent away. These can be recycled five or six times, and the cycle limit has yet to be reached, says Kirkman.  

This is made worse by the fact that, in the UK, waste collection and recycling are not coordinated centrally. They are managed by local authorities, creating inconsistences and hindering closed-loop recycling of materials – especially plastics.

Though plastic recycling is improving – it has increased by 75 per cent in 10 years (according to PlasticsEurope’s 2017-2018 Review) - there is still much to be done.

One way to encourage recycling and add value to plastic bottles and other types of plastic packaging is a deposit return scheme, which could increase recycling of some plastics by 90 per cent, says Kirkman. These are already starting to be rolled out in some areas across the UK.

The environmental spotlight is, quite rightly, on plastic. According to Professor Thompson, discussions now must focus not on eliminating this versatile and durable material completely but on reducing its use wherever possible and making it easier to recycle. “It is important to make sure we avoid knee-jerk reactions and take the right action; we need more evidence to guide us to the right solution,” he says.

Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.

Recent articles