6 November 2025
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Are you familiar with sustainable fashion? Then you’ve likely heard of Lyocell, often hailed as a sustainable fibre and a favourite among eco-conscious fashion brands. But what is Lyocell, and is it truly the miracle material it’s made out to be? COSH! delves into its pros and cons to help you make informed, sustainable shopping choices.
A Soft and more Sustainable Alternative to Cotton
The Advantages of Lyocell
First introduced by the now-defunct American fibre facility Enka in 1972, Lyocell has since become a highly popular fabric choice – and for good reason. Lyocell stands out as an exceptionally breathable material known for its soft texture and luxurious look. Its robustness, absorbency, and hypoallergenic properties make it a practical choice for everyday wear.
One of the most convenient features of Lyocell is its resistance to odours, meaning your clothes stay fresh longer and require less frequent washing.
What makes Lyocell even more versatile is its ability to blend seamlessly with various other materials, such as cotton, silk, rayon, polyester, nylon, and wool. This adaptability has seen Lyocell incorporated into a wide range of apparel, from sportswear and chic dresses to casual jeans, making it a multifaceted fabric suitable for various styles and occasions.
The production process
From Wood Pulp to Fashionable Fabric
Lyocell is a human-made fibre derived from natural materials, specifically from the cellulose found in tree trunks, bark, and leaves. It’s predominantly made from eucalyptus wood pulp, transformed through a chemical process into a pulp that’s then spun into threads and woven into fabric.
Lyocell’s Environmental Impact
Is Lyocell Twice as Sustainable Compared to Cotton?
Lyocell, a common fabric in eco-friendly fashion collections, raises the question of its actual sustainability. According to the Higg Index, which regards Tencel highly (a Lyocell by Lenzing brand), viscose fibres derived from cellulose in wood pulp are twice as sustainable as cotton.
Lyocell performs about 10% better in sustainability than standard viscose, yet both have a higher ‘global warming’ impact than cotton. This could be due to Lyocell’s chemical usage, which is slightly less (10%) than regular cotton, indicating that organic cotton is more chemical-efficient.
It’s crucial to note that Lyocell’s production process is free from toxic chemicals and allows for an impressive 99.5% solvent reuse, ensuring minimal environmental contamination in Europe.
Despite these eco-friendly aspects, Lyocell’s water usage effectiveness is somewhat controversial. While it fares better than regular cotton, the eucalyptus trees used for Lyocell require significantly more water (30% to 50% more) than native trees. This high water demand has contributed to environmental challenges, especially and ironically in regions like Spain, Portugal, California, and South Africa, where eucalyptus plantations and drought are prevalent.
Eucalyptus in Europe and the US
Originally from Australia, eucalyptus trees were introduced to Europe in the 18th century, mainly in Spain, Portugal, and the US. Initially planted to drain swamps and combat malaria, these trees have become controversial due to their high water consumption and impact on local ecosystems.
Why Did Europe Import Eucalyptus?
The global spread of eucalyptus trees in the 18th and 19th centuries was initially celebrated. However, this success brought unintended ecological consequences. Since the mid-1970s, there have been protests against the extensive planting of eucalyptus in Portugal, known as “eucalyptisation,” which has led to the depletion of local water resources.
The introduction of this non-native tree has significantly impacted the environment and biodiversity. The natural inhabitants of eucalypt forests in Australia, including over 50 mammal species like koalas, wallabies, and pademelons, along with more than 200 bird species, were not translocated with the trees.
This omission has led to a loss of biodiversity in the regions where eucalyptus is now grown, exacerbated by climate change challenges. In various countries, the eucalyptus is increasingly regarded as an invasive species threatening local ecosystems, prompting calls for reducing or ceasing its cultivation.
How Eucalyptus Forests Impact Spanish and Portuguese Ecosystems
Research from 2017 undertaken by the Ministry of Environment in Spain showed many negative consequences on Spanish ecosystems because of Eucalyptus tree expansion. We summarised the most important ones below.
Nitrogen Reduction of the Soil
The leaf litter from eucalyptus trees doesn’t decompose easily due to the lack of indigenous invertebrates that can break it down. This leads to the leaves accumulating on the ground and ultimately impoverished soil nitrogen levels.
Disrupting Biodiversity
Eucalyptus trees release biochemical compounds that can adversely affect other species’ growth, survival, or reproduction. This disrupts local biodiversity, as these compounds prevent the establishment and development of different plant species.
Repression of Other Trees
Eucalyptus can colonise open spaces, particularly in areas disturbed by fire, often outcompeting and displacing native tree species. In Portugal, eucalyptus is notably successful in colonising areas disturbed by fire.
Link to Forest Fires and Lyocell Demand
The demand for Lyocell, made from eucalyptus wood pulp, might indirectly contribute to forest fires in Spain and Portugal. Eucalyptus plantations cover around 800,000 hectares in Portugal, constituting a quarter of the country’s forests. These trees now pose significant environmental challenges, including an increased risk of forest fires due to their highly flammable nature and the vast areas they occupy.
Eucalyptus Forest Fires: A Vicious Cycle
Eucalyptus forests pose a significant fire risk due to the accumulation of non-decomposing leaves and bark containing highly flammable oil. Following a fire, eucalyptus trees vigorously resprout, and new plantings are made, creating a challenging cycle to break. Eucalyptus trees thrive in fire-disturbed environments, often at the expense of other species.
In the context of climate change, eucalyptus trees exacerbate fire risks, especially during heat waves, increasing the likelihood of forest fires.
Eucalyptus as an Invasive Species in Spain
In Spain, introducing eucalyptus trees has brought unintended ecological consequences, including the spread of weeds and pests. The species, now listed in the Spanish Catalogue of Invasive Alien Species, significantly disrupts biodiversity. Their role in forest fires further highlights eucalyptus trees’ environmental impact.
Galicia, a region in Spain, experiences about half of the country’s forest fires. Notably, after a devastating fire in October 2017, which saw 5,000 hectares of eucalyptus trees burning (44% of the total burnt area), the Galician government halted the expansion of eucalyptus forests, identifying them as fire accelerants.
This incident shed light on the extensive presence of eucalyptus and pine trees in Galicia, covering double the area of deciduous hardwoods but posing a much higher fire risk – burning at a rate five times greater. This stark contrast underscores the environmental challenges posed by eucalyptus plantations in Spain.
Economic Benefits
Eucalyptus trees offer distinct advantages, especially in the fashion industry. Their rapid growth rate makes them economically beneficial, yielding a significantly higher return per hectare than pine trees. For example, in Galicia, Spain, a hectare of eucalyptus can generate €1,000 annually, while pine trees yield only €300. This high economic value contributes notably to the region’s economy, with eucalyptus production accounting for 4% of Galicia’s GDP.
Ecologically, eucalyptus trees are low-maintenance, requiring neither irrigation nor substantial pesticide use. They thrive even on land unsuitable for agriculture, allowing for efficient land use.
Lyocell’s Sustainability Questioned
Like with most things, there is no straightforward answer, and the topic is debated extensively. Despite its environmental downsides, Lyocell is considered one of the more sustainable materials due to its biodegradability and recyclability.
However, the sustainability factor is challenged by the scale of production. If the fashion industry heavily relies on Lyocell, replacing materials like polyester and cotton, it could lead to extensive forest use and heightened biodiversity issues. Therefore, controlling production volume is crucial for maintaining Lyocell’s sustainability.
For those interested in sustainable fashion, stay tuned for our upcoming article on Tencel, a sustainably produced fibre by Lyocell by Lenzing. And to keep up with the latest articles from COSH!, don’t forget to subscribe to our newsletter!
Would you like to discover more sustainable clothing made from Lyocell? Take a look at our shopping guide and find local clothing in your style and within your budget!
