Plastic and glass to confront
We usually consider plastic one of the world’s worst pollutants, ideally preferring glass, which conveys a healthier, greener idea of our packaging, but… are we sure this is the case?
In 1969, the manufacturer of a very popular sparkling drink decided to sell its product in plastic bottles. How could such a decision be justified at a time when glass ruled supreme and plastic was not yet widespread in the beverage sector?
Simple: the manufacturer in question had already carried out a Life Cycle Assessment (LCA) of the different materials at that time, choosing the one with the least environmental impact.
Since then, several studies have confirmed the thesis that plastic is less harmful to the environment than glass.
Let’s see in detail why
To get a really perfect idea of the context, we have to start from a premise: the perfect material for the food or cosmetics industry does not exist, as it should be made from natural raw materials, be light, cheap, completely recyclable, have low energy consumption during production and distribution, be unbreakable and infinitely reusable… practically… impossible! Despite the technologies of 2021.
In order to understand whether one material is better than another, we need to make a 360° assessment, considering all the different phases of the material’s life, from its extraction, to the production, transport, use and end-of-life phases. Life Cycle Assessment (LCA) helps us to understand how the life of materials used for the production of goods and/or services affects the environment by analysing the following criteria:
- Extraction and processing of raw materials
- Production
- Packaging
- Transport and distribution
- Useful life, product maintenance and reuse
- Recycling
- Final disposal
A number of studies conducted by analysing the LCA of various materials tell us that plastic is currently the most environmentally friendly packaging for the food and cosmetics industry.
Disposable glass is the worst packaging and up to four times more polluting than PET (polyethylene terephthalate).
This is due to its characteristics which cause a use of more energy during its entire LCA. The high specific weight of glass (2.5 g/cm3 compared to PET’s 1.3 g/cm3) means that more energy is spent in the logistical phase of transport and handling, as well as the high temperatures needed to melt glass during production and/or recycling being around 1000-1600°C, compared to 260°C needed to melt PET.
In addition, in recent years, PET processing technology has made possible to achieve extremely thin thicknesses (-48%) compared to 10 years ago, without compromising the technical characteristics needed for market requirements.
So what is the real problem with plastics?
The main problem with plastic is not its life cycle but its ‘death’ cycle or rather, the post-consumer use we make of it. In Europe by 2020, only 42% of plastics will be recycled, and despite constantly improving data, this is not due to a lack of appropriate technology, but to the chronic slowness of politicians and society to take charge of green solutions. This is why the EU is working on a new strategy that proposes to make all plastic packaging recyclable or reusable by 2030.
A strong change that, combined with the implementation of the collection and, above all, recycling chain, could really revolutionise the system. In Italy in particular, 87% of the packaging placed on the market is collected, but only 44% is recycled, giving new life to the plastic; the remaining 43% is still used for energy recovery. There is still a lot to be done and put into practice, especially in terms of organisational policies.
Sources: Corepla, Coreve, Plasticseurope.org, researchgate.net/274070977, researchgate.net/257679872
