Which Material is more Sustainable? -Plastic? Aluminum? Glass?

Which material is more Sustainable?


There are a lot of factors that play into the environmental impact of these different materials. Every material we use affects the environment through habitat disruption or destruction when we mine, dig, or harvest the raw materials. Each material requires energy to be processed and transported to manufacturing centers — and once recycled, they travel varied distances (again) to be re-processed, and different amounts of each material can ultimately be recovered through the process. Each material has a different economic incentive and generates different total greenhouse gas emissions. All of these factors intertwine to create the products’ total environmental impact, which makes them difficult to compare. So, there may be no single “right” answer, but below you’ll find facts and figures to help you navigate the endless shelves of sodas, juices, and waters.


Let’s start by eliminating one of those choices right off the bat — the plastic bottle. In 2007, researchers Peter Gleick and Heather Cooley estimated that satisfying the existing bottled water demand required the energy equivalent of between 32 and 54 million barrels of oil — that means producing plastic bottles each year releases more greenhouse gas emissions than over a million cars on the road. In 2013, the International Bottled Water Association released a study that estimated it took 1.39 liters of water to produce 1 liter of packaged water. While this is an improvement from the 2006 Pacific Institute estimation of 3 liters of water per liter of bottled water, it still demonstrates a worrying amount of water wasted.

One of the most important reasons you should eliminate plastic bottles from your routine is that, while recyclable, plastic bottles take 450+ years to decompose (over 1,000 years, if they’re in a landfill), and their photo degradation releases toxic chemicals into the surrounding environment. While you may be vigilant and recycle each plastic bottle that comes in your path, not everyone will do the same, and the best way to reduce the generation of these plastics is to reduce the demand for them.

Glass and Aluminum:

Glass and aluminum each have positive and negative attributes that can make it tricky to choose between them. At the beginning of aluminum’s life cycle, it exists as a group of aluminum oxides called bauxite. Before it becomes the can your favorite soda is packaged in, it must be mined, shipped to a refinery where materials are separated to isolate alumina, smelted to covert the refined alumina into aluminum, and then fabricated into cans. The United States does not contain any bauxite mines, and so it must rely on importing the ore for processing.

There are, however, significant benefits to purchasing your drinks in aluminum cans — namely they save energy and money. According the Aluminum Association, in 2012, 70% of aluminum cans were made from recycled aluminum. In comparison, making a can out of recycled aluminum requires only 8% of the energy consumed by producing new aluminum.

To date, aluminum is the most recycled material in the world — 55% of aluminum cans are recycled in comparison to just 34% for glass containers. As for the cans that people throw away instead of recycling, many of them get picked up by do-gooders and profiteers thanks to the 5-cent-deposits for returned cans. As for the cans that wind up in a landfill: They can take up to 500 years to decompose, which maybe isn’t so bad considering that’s at least 2000 times shorter than it takes for glass to decompose.

It’s true: Glass bottles take over a million years to decompose. But the silver lining is that — should the glass not get recycled — they are inert in landfills, meaning they won’t leach harmful chemicals like plastics. Add that to the fact that the weight of glass bottles have decreased by 40% in the past 30 years, and glass starts to seem like not such a bad choice after all. According to the Glass Packaging Institute, 100% of glass bottles are recyclable, and can be recycled endlessly without any degradation of quality. This means in addition to their ability to be recycled on an industrial level again and again, you can personally reuse glass without worrying about it degrading and leaching chemicals into your liquids.

One key downside of glass recycling is that used glass is often shipped long distances from local recycling companies to glass recycling plants, adding to their ultimate GHG emissions. And unfortunately, recycling glass is also economically unfeasible in some areas, as issues with quality and the need for special equipment drive up both cost and energy consumption.

So, they both have their pros and cons, but the choice ultimately comes down to what the highest priority is for you. If your primary concern is chemical leaching and the impacts of raw material extraction, glass is probably your best bet (and for the sake of the environment, reuse the glass bottle as much as possible before recycling). If you want to support the industry that is best at inspiring material recovery and can almost always be locally recycled, choose the can.

Your best bet would be to invest in a reusable bottle to save your wallet and the environment!