Oh, if only there was a simple answer to the question of “What is the most sustainable packaging material?” Glass? Plastic? Aluminum? Paper? Does one come immediately to mind? Paper, perhaps? Ah, but then there are all the trees to consider in this. Aluminum? Maybe, but what about all the land that is required to be dug up in order to access it? And, it is non-renewable since it is a metal. Glass? Maybe? Well, its definitely not plastic. Everyone knows plastic is the worst! So yes, maybe glass is the best. It is endlessly recyclable, never loses its quality, and doesn’t leach toxic materials. We don’t have to cut down trees or dig up vast swatches of land to get to it. It’s just melted sand, right?
Unfortunately, it isn’t this simple. There is a very common misperception that glass is safer for the environment than plastic is. The truth of the matter, however, is that every container material choice is a trade off. No one material is the best option.
Let’s explore this a bit in terms of the production of both plastic and glass, focusing on materials used, the production process itself and carbon generation.
The first step in glass manufacturing involves collecting raw materials such as sand (silicon dioxide), soda ash (sodium carbonate), and limestone (calcium carbonate). Some glassmaking processes may also include cullet, which is recycled glass.
These materials are weighed, mixed and then heated to a very high temperature. The molten mixture is then homogenized, formed, cooled and inspected for quality.
Most of the energy used occurs during the melting phase, in which the sand, etc. are placed in a furnace and heated to temperatures of around 1,500 to 1,600 degrees Celsius (2600 – 2800 degrees Fahrenheit). A glass furnace will run 24 hours a day, 7 days a week and cannot be stopped and cooled down during its lifetime (15-18 years), except during periods of maintenance. [i]
The initial step in plastic manufacturing involves obtaining the raw material, primarily hydrocarbons derived from fossil fuels such as oil or natural gas. Other feedstocks, such as bio-based materials, are starting to be used.
The hydrocarbon raw materials undergo a 'cracking' process, in which they are heated and broken down into simpler components, then chemically bonded together in a process known as polymerization.
Once the polymer is formed, it is cooled and cut into small pellets, which are the raw form of plastic most commonly sold to manufacturers.
Manufacturers then melt these plastic pellets and form the mixture into the desired container shape. [ii]
COMPARING ENVIRONMENTAL IMPACT
As we mentioned earlier, there is a trade-off when considering any type of material for packaging. Since there are many different considerations and it can get overwhelming pretty quickly, it is important to keep our common sense about us. In a world filled with sensationalized headlines and clickbait, it's easy to get caught up in the media frenzy surrounding both glass and plastic bottles. Plastic has been portrayed as the villain in the environmental narrative, blamed for everything from polluting our oceans to single-handedly destroying the planet, while glass is heralded as the saviour. So, what do we believe and how to we decipher the truth from the hype?
We are going to focus in on two key considerations: raw materials and greenhouse gas emissions, as these are the two most important contributors to the health and safety of our planet.
GLASS ENVIRONMENTAL IMPACT
In terms of carbon generation, the glass manufacturing industry contributes significantly to global CO2 emissions due to the high-energy intensity of the melting process. Depending on the type of furnace used and the fuel source, a typical glass furnace can emit, on average, approximately 3g of CO2 per 1g of glass produced. This includes direct emissions from combustion and indirect emissions from fuel/electricity use.[iii]
Making glass bottles requires more material than plastic bottles. For example, an 82g glass jar at 3.0 CO2 equivalents per gram has a total impact of 246 grams of CO2 equivalents per jar. A lighter 13.0g HDPE plastic jar using the highest range of 3.8 CO2 equivalents per gram has a total impact of 46.8 grams of CO2 equivalents. The plastic jar has only 20% of the carbon impact of the glass jar. It would take more than 5 plastic jars to equal the environmental impact of one glass jar.
Transportation of glass, which itself generates carbon and other greenhouse gases, uses both more energy and produce more carbon than transporting plastics or other, lighter materials. For instance, a 330ml plastic soft drink bottle contains around 18 grams of material while a glass bottle can weigh between 190g and 250g. Transporting drinks in the heavier containers requires 40% more energy, producing more polluting carbon dioxide and increasing transport costs by up to five times per bottle.
A report by the American Chemistry Council and environmental accounting firm Trucost estimates that the environmental costs – which places a value on dealing with the pollution generated by a product – would be five times higher if the soft drinks industry used alternative packaging like glass, tin or aluminium instead of plastic.[iv]
Additionally, the world is running out of sand. After air and water, sand is our most used natural resource, even more so than oil. It is used to make food, wine, toothpaste, glass, computer chips, breast implants, cosmetics, paper, paint, plastics and more. Sand, like oil and other petrochemicals, is not renewable. To continue producing the above items, we need and generated from mountain rocks, pelted by rain, wind, and rivers for over 25 thousand years.[v]
PLASTIC ENVIRONMENTAL IMPACT
As with glass, the raw materials required for production of most plastic are non-renewable. The exception to this are bio-based materials that are starting to be used for some plastic manufacturing. However, since this is a relatively new technology and not a raw material that can be used for personal care packaging at this time, when we discuss plastics, we are not including bio-based materials in our considerations. (They do offer some very intriguing and exciting possibilities for the future, though.)
The majority of raw materials for plastic used in products such as body butter jars, body lotion tubes and foaming hand soap pumps comes from hydrocarbons derived from fossil fuels such as oil or natural gas. The process of extracting these from the earth, as well as their non-renewable nature, make them less than ideal options for earth safety.
The carbon emissions from plastic production can be significant due to the energy-intensive nature of the process. On average, around 1.5 to 3.6 kilograms of carbon dioxide is emitted for every kilogram of plastic produced.[vi] This includes emissions from the extraction of raw materials, transportation, and the manufacturing process itself.
In addition to these environmental impacts, there are considerations such as micro-plastics, marine pollution and the limited recyclability of plastic.
As we mentioned earlier, there is a trade-off when considering any type of material for packaging. At Tiber River, we are working to reduce our environmental footprint and be more eco conscious by becoming climate neutral by 2026 and carbon negative by 2030. Therefore, our biggest concern is to reduce the amount of carbon and greenhouse gases both our production process and products generate.
So, we choose to use the packaging material that generates the lowest amount of carbon and greenhouse gases, both during production and while in use. This material is plastic.
While it's crucial to acknowledge the environmental impact of plastic bottles, it's equally essential to approach the issue with a balanced perspective. Like any product, plastic bottles have their pros and cons. It is important to acknowledge that their convenience, durability, and affordability have positively impacted our daily lives. While we must address the environmental concerns associated with them, it's equally vital to recognize the benefits they provide, such as lower carbon and other greenhouse gas emissions, safe storage of materials and lower transportation costs, both capital and environmental.
The media's portrayal often magnifies the negatives while overlooking the progress made in sustainability practices and individual responsibility. Plastic bottles, when managed properly, can coexist with a greener future. By embracing innovation, recycling, and responsible consumer choices, we can navigate the plastic bottle paradox and work towards a more sustainable world.