Glass vs. Plastic: Is there a Clear Winner?

By Aubrey Black (Bachelor of Applied Science in Materials Engineering; currently an EIT working in the Zero Waste/Circular Economy field)

If you’re an environmentally-conscious individual, or really any human with internet access, you’re likely familiar with the plastic waste crisis. From Mount Everest to the Mariana Trench, plastic waste has been identified virtually everywhere on the planet. It’s a massive issue that leaves many people wondering what material, if any, is a more sustainable option.

The answer to that question is highly complex and nuanced, and realistically I cannot even begin to answer it in any meaningful way here. But, given that this is primarily a food-related blog, I’ll try to tackle a more bite-sized question: which is a better material for food packaging – plastic or glass?

Glass vs. Plastic food packaging – what’s the difference?

At first glance, it might not seem like much. Both can serve as effective food packaging, offering transparency, impermeability, and food-safe quality. But when we take a deeper dive into each material, the differences become more apparent.

Glass

Glass is made primarily of sand, soda ash, and limestone, which are natural and generally abundant raw materials. The glassmaking process involves melting the raw materials at high temperatures (> 1500°C), and then shaping and cooling the glass into finished products. The initial manufacturing process is energy (and thus emissions) intensive due to the high temperatures required to produce molten glass, as well as the demands of raw material extraction.

However, a major advantage of glass is that it can be reused and recycled repeatedly without downgrading in quality. In fact, recycled glass is often a key ingredient in making new glass products, decreasing the demand for further resource extraction. Additionally, reusing glass products before eventually recycling them helps to offset the impacts associated with their production.

Plastic

Plastic is made from by-products of the petrochemical industry that are processed via the addition of heat, pressure, and certain chemical additives. This process is far less energy intensive than glass manufacturing, but is inexorably linked to environmentally-problematic industries. Furthermore, plastics run into trouble when it comes to the end-of-life material disposal.

In Canada, only roughly 9% of plastic gets recycled. That means 91% of all plastic used in the country ends up in the landfill, or gets released to the natural environment, often after only being used a single time. Plastics that end up in land and aquatic environments take centuries to break down, and result in the generation of microplastic particles. Both macro and micro plastic pollution have detrimental effects on wildlife.

Plastic recycling sounds promising in theory, but is hindered by significant economic barriers – it is almost always more cost effective to produce virgin plastic than to recycle existing material. Furthermore, plastic recycling downgrades the quality of the material. In that sense, it’s really only delaying, rather than preventing, the eventual disposal in landfill.

And the winner is???

As you’re probably gathering, this a complicated issue! There’s no definitive answer as to which material is the better choice environmentally or functionally. While glass can be reused and recycled effectively, plastic is lighter and less fragile, making it a safer choice in some cases, and making it cheaper and less energy-intensive to ship. There are trade-offs to both materials that must be considered when deciding between the two.

LTF believes in reducing their footprint on the planet as much as possible, including waste generation. That’s why their products don’t use any single-use plastics, and are instead packaged in reusable glass jars. When you finish your cheese or yogurt, you can reuse your jar at home, return it to LTF for a discount off your next purchase, or recycle it as a last resort. If you’re going to recycle glass packaging, ensure it’s clean, and sort it according to the proper practice for your jurisdiction (recycling practices may vary by municipality/region).

Realistically though, glass packing isn’t always accessible or feasible for all products. Regardless of the type of packaging materials you end up with in your home, the most sustainable steps you can take to address packaging waste are:

1. Reuse items to extend their lifecycle and delay disposal - reusing an existing item can decrease demand for the production of equivalent new items
2. Understand the best practices for disposal where you live - material is more likely to actually be recycled if it is clean, sorted, and brought to the correct location (ie. curbside collection vs. recycling depots)