Every year, millions of tons of packaging waste end up in landfills and polluting the environment, posing a risk to the health of the planet and humans alike. Growing concerns have intensified stakeholder pressure for sustainable options, making packaging materials a critical focal point. Packaging is a customer’s first impression of a product, and as we’ve heard before, it only takes seven seconds to make one. With growing demand, sustainable packaging can have a significant impact on brand reputation making it an important decision for a business. While plastic remains a popular choice, glass is often touted as a sustainable alternative. So which is better: plastic or glass?
Plastic
Plastic is everywhere. Quite literally, microplastics have been found everywhere on this planet, harming animals, humans, water, soil, and other environmental metrics. According to the United Nations Environment Programme, 400 million metric tons of plastic waste is produced every year. A consumer demand for less plastic has led companies to ponder what they should use instead.
It can be difficult to envision a world without plastic. However, plastic didn’t become a dominant material until after WWII, especially with plastic production tripling between the 1970s and the 1990s. In merely a few generations, plastic has reigned as a cheap and versatile material. It has also become a major environmental concern. Plastics are typically made from fossil fuels which are refined to ethane and propane and treated with heat to create ethylene and propylene. The materials can then be combined to create polymers which are then mixed with other materials to be melted and create the plastics.
Environmental concerns associated with plastics occur at every stage of the product. Extracting fossil fuels for plastic production is an energy-intensive process that produces over 3% of global greenhouse gas emissions. When the product is being used, chemicals like Bisphenol A (BPA), and other substitutes, are often a concern, especially with food and drink. Furthermore, plastic doesn’t biodegrade like other materials. It stays in the environment, whether it be the landfill or the oceans, for hundreds of years of decomposition where it simply gets smaller and never truly goes away. Plastic pollution can be fatal to wildlife, reduces soil health, contaminates groundwater, and can have serious health impacts on humans too.
Glass
While glass has always been a naturally occurring material, human-made glass has been around for centuries longer than plastic and is often seen as a sustainable alternative to plastic, particularly concerning its recyclability where it’s able to be fully crushed and melted back down again.
Glass has become a popular alternative for sustainable packaging, and in some cases, the original material for packaging like bottles and jars. Glass is primarily made of limestone, sand (silica), and soda ash (sodium carbonate). The ingredients are mixed, melted, and shaped.
Similar to plastic, raw material extraction can be detrimental to the environment. Additionally, glass has a much higher melting point than plastic, requiring a vast amount of energy to produce a product. Plastic can require up to 200ºC to melt while glass requires temperatures around 1600ºC. However, glass, while it can be harmful to your health breathing in silica during raw material extraction, is non-toxic.
How much does recycling matter?
End-of-life disposal can impact a product’s environmental impact by diverting products from the landfill and polluting the environment. Using recycled materials can avoid emissions associated with raw materials, such as extraction, processing, and transportation. Recycling rates vary by region, country, and even locally due to different policies, infrastructure, and consumer behavior which can impact the sustainability of a product.
Plastic Recycling Rates
US: 5-6% of post-consumer plastic
UK: 81% of post-consumer plastic and 86% of plastic packaging
EU: 39.7% of plastic packaging
Using recycled plastic can save between 30% and 80% of emissions associated with virgin plastic processing and manufacturing. Recycling plastic eliminates emissions associated with raw materials and diverts plastic from landfills and polluting the environment. However, it’s important to note who your customers are and what their end-of-life disposal options are. For those that have recycling programs available to them, further education on how local sorting works is important for successfully increasing recycling rates.
Glass Recycling Rates
US: 31.3%
UK: 74.2%
EU: 80.1%
Glass is often touted as 100% recyclable, alluding to the fact that glass containers can fully be crushed and remelted. The energy required for the high melting points of glass is a significant contributor to emissions associated with producing glass, however, recycled glass has a lower melting point. For every 10% of recycled glass used to make new bottles reduces emissions by 5% and energy use by 3%. Reusability can also play a part where refillable glass bottles use about 93% less energy based on 25 uses. Additionally, crushed glass can be used without melting it like in concrete, backfill, and drainage, avoiding the energy and emissions associated with the melting process.
End-of-life disposal may require consumer education to ensure the most sustainable packaging option is chosen. Whether you choose plastic or glass, recycling and using recycled materials can have significant environmental savings.
Shredded bottle caps at a waste recycling plant.
But what about weight?
We haven’t addressed one of the key factors at play: the amount of material required. If you’ve ever held a plastic bottle and a glass bottle of the same size, you’ve probably noticed the glass one is much heavier. This means it requires a lot more material for a glass container than a plastic container. This not only impacts emissions associated with creating the product itself, but it also impacts transportation costs.
Glass vs Plastic: Conclusion
The comparison between glass and plastic packaging reveals the trade-offs with environmental impact, cost, and recyclability. Glass offers advantages such as non-toxicity, potential for high recyclability, and maintained quality when using recycled materials. However, it requires more energy and material and can negatively impact emissions associated with transportation due to its weight. Plastic, on the other hand, is lightweight, durable, and has lower associated emissions with production. However, it never goes away, only breaking down into smaller pieces. This is a threat to the health of ecosystems and poses health risks to humans. This may lead to consumers that are conscious about the potential health impacts to prefer an alternative material to plastic, especially concerning food or drink. A study found on average, a one litre plastic bottle of water contains over 240,000 pieces of plastic.
From a purely emissions-based perspective, plastic may seem preferable. However, plastic is a material whose toxins can contaminate soil and water. While glass recycling rates leave room for improvement, improvement provides an opportunity to further reduce environmental impact without compromising quality. It’s crucial for both plastic and glass to employ ethical practices and proper environmental management during raw material extraction which is often seen as a negative for either material. Plastic remains a focal point due to its environmental hazards and warrants continued caution. Moreover, new technologies are providing alternatives to both plastic and glass. Bioplastics, mycelium, compostable packaging, hemp, and paper are just some of the alternatives that may better suit your product. Conducting a Life Cycle Assessment (LCA) is essential for choosing the most sustainable packaging for your product and it provides the necessary data to support your claims to consumers and investors alike.
