When it comes to “sustainable packaging,” there’s no one-size-fits-all answer. It’s important for brand owners, food producers and manufacturers to consider very carefully what packaging format they use and to make an informed decision based on the reality of our current waste management infrastructure and level of public understanding, says Richard McKinlay, head of circular economy at resource recovery specialist Axion. “They also need to understand what actually happens to their materials at end-of-life and what their environmental impact could be.”
Specifically, are biodegradable plastics better for the environment? It’s a complicated issue. “Plastic materials that at end-of-life can completely break down naturally and disappear harmlessly may sound like the ideal answer. People hear terms such as ‘biodegradable’, ‘bio-plastic’ and ‘compostable’ and assume that these plastics are more ‘environmentally-friendly,’” he says. “However, the reality is not so simple.”
The main issue, he says, is a lack of understanding of the nature of compostable or biodegradable plastics and what bio-plastics are, particularly in terms of their specific applications and the specialist treatment process needed to deal with these materials.
Bioplastics are made using renewable feedstocks rather than being derived directly from oil. Bioplastics can be used in the production of conventional polymers that can be recycled, such as recycled PET, or biodegradable polymers such as PLA.
While it may seem obvious that selecting a bioplastic is the most sustainable option – there is a clear benefit from not depleting a non-renewable source – many petrochemicals are a by-product of the oil refining process. “While we still live in an economy that is so heavily reliant on oil, it may be better to make use of its by-products rather than let them go to waste,” McKinlay says. “Bio-plastics are not free of environmental impact, and the carbon emissions associated with growing crops and converting these into the required chemicals needs to be taken into account.”
More thoughts from McKinlay:
- “Compostable” and “biodegradable” are more or less synonymous terms and mean that the material will completely break down under certain conditions. The key to understanding any potential benefit is to know whether the polymer will easily break down, say in a home compost heap, or if it has to be treated in an industrial composting facility.
- Many plastics that are described as biodegradable or compostable have to be collected and separated from the rest of the plastic waste and be sent to a purpose-designed industrial composting facility where they can be broken down successfully. These facilities exist for food waste, but ensuring that compostable packaging reaches them can be challenging.
- Consumer confusion over what materials can and can’t be recycled is another big issue. Is this plastic water bottle made from a biodegradable plastic or “conventional” plastic, like PET? Does it go in the recycling bin or with the food waste collection?
- Currently, throughout the UK there is a good collection and recycling infrastructure for PET bottles and this can be accessed by most people through curbside collections. But the infrastructure for food waste collections is not as well-established. For water bottles made from biodegradable plastic to be correctly recycled, a public communication campaign would be required so that people understand that biodegradable plastic should go in with food waste, and more food waste collection facilities in public places would be needed.
- Some packaging such as that made from starch, will readily breakdown in a less controlled environment. However it is not possible to switch completely to these type of materials because they are not suitable for all applications. For example, kitchen/food recycling caddy liners are starch-based and will degrade in a home composting system. However this material would not be suitable for use in packaging as it would quickly start to break down when wet.“Ultimately it has to be down to infrastructure investment, public education and behavioural changes,” McKinlay says. “Plastics are an inherent part of our lives and not ‘all bad.’ Their responsible use and disposal/recycling should be a top priority.”