This topic is frequently debated on social media, with comments revealing a general lack of understanding regarding the reasoning behind Europe’s decision to choose plastic (PET) over glass for beverage containers. Consumer perception clearly favours glass over plastic and according to a 2020 European Consumer Survey, the majority of EU residents think that glass is the most environmentally friendly solution. The question is, are they right?

Glass is made from melting a type of sand. Contrary to popular belief, the sand used to make glass does not come from sandy beaches or deserts. Silica sand is mined, and it is in fact the most used resource after water on the planet. Silica sand mining is known to cause considerable harm to the environment including severe land deterioration, adverse effects on biodiversity, and water pollution. As a resource, it is widely abundant worldwide, but the mining process incurs significant cost and environmental overheads.

Glass manufacturing requires huge amounts of energy. Glass typically melts at temperatures between 1,400°C to 1,600°C while plastic melts at just 250°C. The energy (usually from fossil fuels) required to melt glass or sand is much higher which means significantly higher costs and a more significant impact on the environment. Expressed as a simple ratio, the production of one glass bottle consumes about six times more energy than the production of a PET bottle.

Making PET plastic starts with drilling or fracking for crude oil. The crude then needs to be refined at a refinery through fractional distillation to separate the oil into various components, one of which becomes PET through a process called polymerisation. The energy required to produce PET includes that used in drilling, transportation to a refinery, the refining process itself and the final polymerization process.

After all that, the material is transported to a bottle making factory and finally the end product is completed, resulting in a lightweight, durable, water and bacteria-resistant product its fair share of pros and cons.

An urban myth about glass is that we can safely dispose of crushed glass in the sea as it does not pollute. While it does not pollute, we would be throwing away vast amounts of energy we used initially to produce the glass. The way forward for glass use must include recycling but the economic variables must make sense. Although there is a significant volume of recycling, it is often still cheaper to produce virgin glass from sand rather than from recycled glass.

Transportation of any type of beverage container also plays a significant role in its cost effectiveness as well as on its environmental impact. Glass, being much heavier than plastic, requires much more energy to move around. This is compounded further with bottle recovery systems as the beverage container has to be delivered to the outlet and then collected after use to be transported to the recycling facility.

For example, it takes approximately 12 kilograms of glass as opposed to 90 grams of plastic to deliver 30 litres of a product. Glass is also fragile and susceptible to breaking and chipping, so the handling risks involved are much higher. Plastic can easily be crushed reducing its volume substantially while the weight factor is kept relatively low for transportation. If glass is crushed or broken on collection it becomes useless as different coloured glass is mixed together, impossible to separate which is essential for recycling.

Glass bottles have the advantage that they can be returned and refilled but the perception that this can be done indefinitely is inaccurate at best. In practice, a glass bottle is typically refilled between 12 and 20 times at most before becoming chipped and scratched. The actual number depends on the manufacturer’s marketing decisions. Scratched bottles will appeal much less to the consumer.

Each bottle also has to survive the 40 or so journeys involved without breaking for this to happen. Besides the transportation overhead, reusing glass containers involves using large quantities of water and detergents to wash them thoroughly. This adds considerably to the environmental impact. For feasible recycling, glass containers first need to be separated by colour. This process results in more time consumed as well as energy and more risk handling the material.

Recycling plastic requires much less energy due to the lower temperatures required to melt the raw material, however, plastic cannot be endlessly recycled like glass or aluminium. Each re-melting shortens the chain of molecules that make it up and it will eventually reach a stage when it can no longer be recycled and either ends up in a landfill or is incinerated. On the plus side, while glass recycling requires huge amounts of water, plastic recycling uses the same water many times over.

Aluminium cans are a great contender as they can be recycled indefinity. The downside is that once an aluminium beverage container is opened, the contents have to be consumed as it cannot be resealed as can be done with glass or plastic. Aluminium containers can be repeatedly recycled with no loss of quality and recycling aluminium cans saves up to 95% of the energy required to produce a new can and also does away with the need for mining and transporting new material. 

Aluminium is more expensive than plastic by about 25-30% which is an obvious barrier to adoption. Another disadvantage with aluminium cans is their limited sizes while PET has a practically infinite range of sizes and shapes. The biggest downside of aluminium remains the vast power needed in the smelting process during production which needs temperatures around 660°C, not as high as for glass but high, nonetheless. Producing virgin aluminium cans requires far more energy than recycling them which makes this type of packaging ideal for recycling.

In conclusion, no beverage container is perfect. All the available options carry an environmental impact, regardless of what we do and the technology we use. On the other hand, taking into consideration the environmental impact in the initial production, and the viability of the recycling process as well as economic viability, the EU’s choice seems to be currently the best solution.

Marcel Mizzi is a council member at the Malta Chamber of SMEs.