Viscose, Rayon, Lyocell – there’s many names for these semisynthetic plant-based fibers, and many more methods to manufacture them. This makes impact generalizations difficult.
What are cellulosics and where do they come from?
Cellulosic fibers are a range of semi-synthetic materials commonly made from fast-growing trees like eucalyptus, beech, pine and other plants like bamboo, soy and sugar cane. To make most types of cellulosics, the plant pulp is chemically dissolved into a sludge before being reformed into fiber. Thus, even though cellulosic fibers may be plant-derived, they still require significant processing to attain a wearable state.
What are the environmental impacts of cellulosics?
Each type of fiber’s sourcing, production and finishing impacts are very different, making generalizations difficult. While it is true that cellulosics are derived from natural, renewable sources, this doesn’t necessarily make them more sustainable. Wood pulp production’s impacts on ecosystems and biodiversity are also of concern. More than 150 million trees are logged each year to make viscose, many of which come from carbon and species rich forests.
Furthermore, many cellulosics must often undergo heavy, and often dangerous, chemical treatments. This means that substances – such as the highly toxic carbon disulfide – have to be carefully recovered. Mishandling these chemicals may also mean releasing sulfur fumes into the air and into waterways. Not only is this bad for the environment, but it puts workers at high risk for poisoning. Here, closed loop production is absolutely critical to ensure efficient use of these chemicals and that they do not end up in the environment. Successful chemical recovery largely depends on where production facilities are located and how stringent worker safety laws are.
Are there more sustainable cellulosic alternatives?
Firstly, cellulosics are technically renewable, recyclable, biodegradable (albeit slowly) and serve as a form of carbon sequestration, meaning they already have a strong potential in terms of sustainability. Also, growing the raw materials that later form cellulosics requires far less inputs when compared to many fully-natural fibers. Eucalyptus trees, for example, grow rapidly and require very little inputs in terms of water, pesticides and fertilizer. And not all sourcing is problematic, whereby several organizations are working with the forest industry’s biggest customers to reduce the textile industry’s impact on ancient and endangered forests.
There’s also innovative work being done to develop alternative fibers made from waste such as recycled fabrics and agricultural residues, as well as chemicals-free production. That leaves fiber production’s chemicals impacts. Here too, better control technologies can help reduce chemical impacts. Some familiar proprietary brands that are worth looking out for include Spinnova, Modal, Tencel and Lenzing Lyocell which utilize mechanical separation as well as “closed loop” processes that allow for a near total recovery and reuse of chemical inputs, making for a more environmental process overall.
The Forest Stewardship Council (FSC)
The FSC is an international non-profit organization for the responsible management of the world’s forests. It hosts a global program of market-based forest certifications
The EU Ecolabel is a voluntary scheme for product certification including cellulose fibers, and is managed by the European Commission
Illustration: Kiki Fjell