PACKAGING: THE TRUTH ABOUT GLASS

PACKAGING: THE TRUTH ABOUT GLASS

Glass: often deemed the more ‘sustainable’ option for being nontoxic and infinitely recyclable, but it’s not all good news. From carbon impact to recycled content, glass’s impact on the planet is not one to be taken lightly.

THE GLASS VS PLASTIC DEBATE: WHY DO CONSUMERS TEND TO FAVOUR GLASS OVER PLASTIC?
Glass is often seen as a more environmentally friendly alternative to plastic because we have a big issue globally with plastic pollution. This has mostly been driven by the disposal of single use plastic which tends to end up in our oceans, soils and in our food chain. Moving away from single use plastics is a good thing, but we need to recognise that not all plastics are bad, and that sometimes the alternatives are not always as green as you think. In fact, per ‘unit’, a plastic bottle has a much smaller carbon footprint than a glass bottle. On the other hand, glass is infinitely recyclable making it a popular choice from that point of view.

CAN YOU TELL US MORE ABOUT THE CARBON IMPACT OF GLASS?
Glass is made in very large furnaces that create on average 300 tonnes of glass a day. They operate by being continuously heated in order to melt the raw ingredients (sand, limestone and soda ash) into molten glass which is then poured into moulds. The furnaces are never switched off – and in the course of one day natural gas is continuously burned to create the temperatures needed to melt the virgin raw materials, releasing 62 tonnes of CO2. On top of this we have ‘process CO2’, which is the emissions given off by the melting of the raw materials, which is approximately 185kg per tonne of glass. That’s an extra 55 tonnes of CO2 a day!

ARE THERE ANY ISSUES WITH DIGGING UP SAND TO MAKE VIRGIN GLASS?
I wouldn’t say that mining the raw materials for making glass is necessarily bad because they are very abundant. However, mining does have a physical impact on the landscape and surrounding environment as well as associated emissions of excavation that add to the overall footprint of glass. When recycled glass is created, you don’t have to mine for raw materials – existing glass is melted down and reshaped.

HOW DIFFICULT IS IT TO MAKE RECYCLED GLASS?
It’s no more difficult to make recycled glass than virgin glass, but the issue in the UK is that we don’t have enough good quality recycled clear glass (cullet) to make clear glass bottles with high recycled content. At the moment, if you want a glass bottle with a high recycled content you need to get green glass. Dark glass is good, but that doesn’t work for a lot of products and brands – especially in the food and drinks industry where high quality, crystal clear glass (known as flint or extra-flint) is favoured.

The manufacture of flint glass in the UK is about 65% of the glass production, but a lot of that is exported in the form of finished products and actually what we have in our recycling bins are high percentages of green glass and brown glass – mostly because we import and consume products in these containers (think beer and wine). To add to the issue, we don’t recycle enough and we have moved away from using bottle banks and now have co-mingled recycling. You might think this makes it easier for you, but it means that the clear glass gets broken and mixed up with other colours, making it more difficult to separate and get a good quality of colour specific cullet.

If you look at any bottles on your shelf you will see they are very clear with no ‘tinge’ of any other colour and no blemishes. In the industry this is called ‘extra flint’ and generally required for all premium products. If you have one of our bottles, you’ll notice that it has a slightly green tinge and possibly some small air bubbles or blemishes. Allowing these small blemishes through the quality reviews means fewer glasses are rejected in the factory, further reducing the carbon footprint of each one.

Recycled glass

WHY IS RECYCLED GLASS SO MUCH BETTER THAN VIRGIN GLASS?
The advantage of glass made from cullet (recycled content) is that it takes much less energy to melt down and there are no process emissions. Basically, emissions from glass go down as the recycled content goes up! This does depend on the efficiency of the furnace but as an example: every glass bottle we have made saves 0.5 kg (40%) of CO2 emissions per bottle compared making it from virgin materials. For the bottles that we will require in future we will save over 100,000 tonnes of CO2 per year.