As companies strive to make their products more sustainable, many are turning to cork as their new material of choice. Products like cork binders, cork yoga mats, cork furniture, cork purses, and cork shoes are popping up in shops left and right, touted with the claim of being environmentally sustainable- because they’re made of cork. Are these claims simply a marketing ploy, or is cork really that sustainable?
THE GOOD:
Cork is made from harvesting bark from cork oak trees. Harvesting the bark doesn’t damage the trees and also doesn’t require the trees to be cut down, allowing them to regenerate bark to be harvested again. It takes the trees around nine years to grow back the bark, and this nine-year cycle can go on for nearly 200 years.
As the cork oak trees regenerate and grow, they absorb and retain carbon dioxide from the atmosphere. The 2.3 million hectares of cork oak forest scattered around the world retains around 14.4 million pounds of carbon- an amount equivalent to burning 720,000 pounds of gasoline. The forests also serve as vital hotspots of biodiversity, according to a 2014 study of the material.
In addition to cork trees being inherently regenerative, they also require very few inputs. They grow naturally without the need of man-made irrigation, pesticides, fertilizers, or pruning. This allows the material to have a very low carbon footprint without contributing to the pollution of waterways (like most crops and materials do).
Picture courtesy of the Cork Forest Conservation Alliance
After the cork is harvested, it is sent to a factory to be dried, boiled, and processed. Processing is generally a very carbon intensive process, but in the case of cork, it isn’t. According to the Cork Forest Conservation Alliance, 90% of the energy needed to process the cork comes from burning a naturally occurring byproduct of the processing- cork dust. This greatly reduces emissions and waste, allowing for a more circular system of production.
After processing, cork is then made into the products we see on store shelves- furniture, flooring, binders, shoes, backpacks, yoga mats, coasters, etc. The possibilities of cork are endless because it’s a naturally impermeable, durable, and insulating, allowing it to be suitable for a multitude of uses. It can even be used to construct buildings.
THE (POTENTIAL) BAD:
It’s obvious that cork is sustainable in terms of its production and processing, but what about its disposal? Cork products can either be recycled into new products or composted. However, this isn’t always the case. Some products are made with other additives, such as adhesives, that render the cork unable to compost. If you have cork flooring, for example, you probably used adhesive to install it, making it non-compostable (unless you used some form of a compostable adhesive).
To ensure the cork product you’re buying is compostable, make sure it is made from pure cork, and make sure you’re buying from a company that is transparent about the materials that are used in making their product. The best way to ensure that the product you’re buying is truly compostable and/or recyclable is to buy products from small, local businesses and craftsmen who are more knowledgeable about the products they sell compared to typical stores.
Kayla Guilliams
Is the blog manager for Zero Waste Club, combining her love for writing with her passion for all things environmental sustainability. She is currently a student at the University of North Carolina at Chapel Hill where she is studying journalism, environmental studies, and food studies in hopes of building a career in environmental activism. You can find her on Instagram as @kaylaguilliams.