As the world collectively looks to ditch plastic, you may be asking yourself “But, is glass sustainable?” And rightly so. There’s a reason packaging shifted towards favouring plastic. Namely, it’s cheap to make, lightweight, durable and easy to transport – all of the things glass is not!
Find out why glass is bad for the environment and what to use instead.
How glass is made
Mixing sand with recycled glass (cullets), soda ash and limestone then heating it in a furnace at a whopping 1700°C (3090°F) creates glass (1). To make ovenproof glass, bulletproof glass or crystal, other ingredients can be added. However, doing so usually makes the product not generally recyclable. Next, the molten glass is then processed, set and cut into the desired shape.
Virgin glass uses non-renewable materials
Glass is made from a fine sand called silica; a type of quartz that’s broken down by water and wind over millions of years. Sand mining is horrendous for local eco-systems as it decimates local fish breeding grounds and sand bars that feed birds and seals. Sand dredging causes beaches to shrink and has even led to bridges collapsing. As a result, it’s considered to be a global environmental crisis as populations increase and urbanisation continues (2).
Emissions from melting
The biggest environmental impact from glass comes from making the stuff. Melting the raw materials down produces Carbon Dioxide as well as Nitrogen Oxides, a contributor to smog. Moreover, other environmental concerns of glassmaking are water pollution and the use of non-renewable materials such as sand and minerals. A glass furnace has to run 24/7 and can’t be stopped or cooled down during its lifetime (15+ years) (3). Just imagine how much energy this uses, most of which comes from fossil fuels.
Emissions from transportation
Glass is significantly heavier than plastic and requires more fossil fuels to move the same product. Another glass sustainability issue stems from food waste; any food lost due to glass breakage is a huge waste of resources.
Glass takes one million years to break down. Yep, one MILLION
You read that correctly. Glass takes one million years to breakdown (4). Glass artefacts have been found in Egypt from as far back as 13th century B.C. If you thought plastic was bad, imagine how long a wine bottle tossed in the trash could sit in landfill!
Recycled glass is more sustainable
Glass is infinitely recyclable. While reusing an item will always be the most sustainable choice, glass’s high recycling credentials make it a more sustainable choice than other materials. Moreover, recycling glass conserves natural materials and requires lower temperatures than melting virgin glass, using up to 40% less energy.
Is glass ~actually~ recycled?
As with most environmental issues, it depends on where you are in the world:
- According to the US EPA, America only recycles 33.9% of the glass (5).
- Australia manages to recycle about 56% of its glass usage (6).
- Europe boasts glass recycling rates as high as 90% (7).
Glass is part of the single-use model that we need to disrupt
Glass isn’t the problem. This is because even with perfect recycling rates, the single-use system still requires huge amounts of energy to collect, transport and recycle the glass into another product. Better options include:
- Business recycling – also known as the ‘milkman model.’ This is where a business collects it’s own containers and re-uses them in their production.
- German Pfand system – Customers pay a surcharge for a glass container included in the price which they receive back when they deposit the bottle in a kiosk or at a store. Bottles are washed, sterilised and, finally, returned to the manufacturer.
- Bulk buying – Bringing your own container, cotton bag, jar or bottle to a store that sells in bulk to refill.
Is glass sustainable? Pros and Cons
- Infinitely recyclable.
- Doesn’t leech toxins into contents.
- Uses less energy to recycle than create.
- Widely recycled.
- Glass takes one million years to decompose.
- Made from sand dredged from coastal habitats.
- It takes more resources to create glass compared to plastic.
- Heavy and, therefore, requires more fossil fuel to transport.
- Breaks easily which can lead to food waste.
- Often not effectively recycled and expensive to do so.
- Some glass types aren’t recyclable.
Verdict: So, is glass sustainable?
Glass isn’t the problem, our single-use system is. Although it takes a lot of resources to create and ship around, it’s environmental impact diminishes the longer you use it or if it can be recycled locally.
Remember, glass is sustainable if you’re planning to reuse it over and over again. However, glass isn’t sustainable if it’s single-use or your local area doesn’t recycle glass.
Eco Action steps:
- Avoid using glass as a single-use item.
- Buy second-hand or recycled glass items if you need something new such as mason jars or a carafe. Better yet, upcycle it!
- Look for local businesses who package products in glass and pick up or collect the empty containers e.g. local milk delivery.