Lyocell and many other ‘artificial’ fibres (half natural and half synthetic) are being brought to the market as a sustainable solution for the fashion industry: they offer a less pollutant and a more breathable product compared to synthetic fibres, and use somehow ‘less water’ and give a softer feeling than cotton.But is it really such a miracle material? COSH! takes you through the pros and cons.

Soft, sustainable alternative for cotton

The advantages of lyocell

Lyocell was first developed by the American Enka in 1972 and has since gained a lot of popularity. It is often used as a more sustainable alternative to cotton and silk, it is soft to the touch and has a luxurious appearance. Lyocell also blends well with other materials including cotton, silk, rayon, polyester, nylon, and wool.

It can be found in sportswear, chic dresses and jeans, being a versatile and very breathable material. Lyocell is also sturdy, absorbent, hypoallergenic and smells very easily, so you don't have to wash your clothes as often, which is good for the environment.

The production process of lyocell

From wood pulp to fibre

All man-made plant based textiles are made by transforming natural materials containing cellulose (bamboo, birch, cotton plant waste; tree logs, barks, leaves, etc) into fibres. These natural materials are ‘resolved’ through a chemical process, obtaining a mass that is spun pressing it through a sieve to create the filaments that will later be woven into a fabric, these are generic viscose types.

However, specifically for lyocell, no toxic chemicals are used in production and 99.5% of the solvent can be reused over and over again..

Eucalyptus trees in Europe and the US?

Where is lyocell produced?

Many lyocell fibres are produced from Eucalyptus trees. This fact is opening new questions about the impact eucalyptus trees have on new European environments, especially knowing that this tree is native from Australia and few eucalyptus insect pests came with the eucalyptus to their new environments. More than 50 Australian mammal species that normally live in eucalyptus groves, including koalas, wallabies, and pademelons, as well as over 200 bird species, were not imported along with the Eucalyptus trees. As such the Eucalyptus forests pose a threat to local biodiversity as well as a fire hazard. Read more on this in the following article.

The environmental impact of lyocell

Is lyocell twice as sustainable compared to conventional cotton?

According to the Higg Index, viscose fibres score twice as good on sustainability as non-organic cotton. Lyocell also scores about 10% better than regular viscose. But the overall score for 'global warming' of both lyocell and viscose is actually higher. On the one hand, they are better because they need less water than regular cotton, but they use an almost equal amount (only 10% less) of chemicals than regular cotton. This actually means that organic cotton uses fewer chemicals than viscose or lyocell.

Moreover, it is a tree that requires a large amount of water from the soil (30% to 50% more than native trees). This is contradictory, because if you compare the amount of water required with that needed for regular cotton, for example, Lyocell comes out better. The tree's water consumption is the cause of a huge environmental problem that has developed in recent years and is found in Spain, Portugal, California and South Africa.

The reason why the eucalyptus is preferred in the industry of paper and fashion is that it grows at a much faster pace than native trees. As a consequence, the revenue of 1 hectare eucalyptus per year is €1000 compared to the revenue of pine trees which is €300, pine can be used for viscose fabrics. To be able to harvest this amount of eucalyptus, you have to wait ten years whereas it takes 30 years for the pine trees. In the Spanish region of Galicia, eucalyptus trees provide 4% of GDP and the region is heavily dependent on the production of this material.

The impact of Eucalyptus trees on the European ecosystem

The arrival of Eucalyptus in Europe is recorded in the 18th century, and since then has spread in many countries, mainly in Spain & Portugal. Now, especially with the climate change challenges we are facing, the Eucalyptus has become a bigger danger to many ecosystems. In many countries in the world, it is now considered an invasive species that needs to stop its cultivation areas or even reduce them.

Why did they start importing Eucalyptus to Europe in the first place?

Plantation eucalypts are grown in rotation periods of 12 years, during which time the undergrowth is cleared at least twice. “In a native oak forest you would find, in one hectare of woodland, at least 70 or 80 species of plant,” says Pedro Bingre, the regional director of Portugal’s major environmental group. “In a eucalyptus forest, you would hardly find more than 15.”

In fact, one of the reasons why in the 18th- 19th Century the plantation of eucalyptus had a great success around the world, is because of its high consumption of water, it would help to drain swamplands and reduce the incidence of malaria. But it was the drying up of village water supplies that sparked a groundswell of opposition to the “eucalyptisation” of Portugal. “Ever since the mid ’70s people have been protesting,” explains Bingre.

We found a study from 2017 from the Ministry of Environment in Spain that was answering these questions and more. It confirmed the eucalyptus as an invasive exotic species, given the adverse effects they cause on ecosystems, as listed below:

Effect number 1

The difficulty of decomposition of its leaf litter

Due to the chemical composition of the leaves of the Eucalyptus species, there are no native invertebrates capable of consuming them. As a consequence, this leads to a drastic impoverishment of nitrogen in the soil. >>

Effect number 2

Alteration of the properties of the soil.

Eucalyptus creates biochemical compounds that influence negatively on the growth, survival or reproduction of other organisms, so limits establishment and/or growth of other species, restricting their growth. >>

Effect number 3

Acidification and soil degradation

Eucalyptus trees altered to a greater extent than forest fires of native Quercus robur oak forests. Moreover, a significant decrease in soil water balance has been demonstrated compared to native vegetation, particularly in dry, arid or arid climate dry, arid or semi-arid climates. >>

Effect number 4

Loss of biodiversity, both plant and animal

the leaves of eucalyptus trees that reach the rivers are toxic to most animals. This characteristic is common to any type of forest monoculture, although due to the sum of the biological and physiological properties described above for the Eucalyptus species, this loss may be more pronounced in these cases.


Is the growing demand for lyocell and tencel related to Spanish and Portuguese forest fires?

Eucalyptus covers ± 800.000 ha in Portugal and this represents 1/4th of the Portuguese forests. The trees were originally planted to drain marches but have an unpleasant aftertaste for the future.

Due to the large quantity of dried leaves and bark that fall from the trees to the ground (which do not decompose), there is a great fire risk in eucalyptus forests. The leaves contain an oil that is highly inflammable. After a fire, the trees sprout intensively and many new plantings are made. This can lead to a vicious circle which is difficult to break (eucalypts favour fire and fire favours eucalypts over other species).

So eucalyptus is not a nice tree in the face of climate change. When there are more heat waves, the chances are high that a tree will catch fire and then a forest will quickly disappear into the fire.

Weeds and pests associated with Eucalyptus have also been inadvertently introduced. In short, all exotic species of the genus Eucalyptus disrupt biodiversity in the transformed environment. Therefore, all species of the genus Eucalyptus are considered to be environmentally transforming species through the impact they have on the composition and diversity of native species.

It has therefore been decided to include all species of Eucalyptus naturalised in Spain in the Spanish Catalogue of Invasive Alien Species. In Spain, 50% of forest fires occur in Galicia. After a major fire in October 2017, the Galician government stopped the expansion of eucalyptus forests. At the time, the government also called eucalyptus a fire accelerant.

During that forest fire in 2017, 5,000 hectares of eucalyptus burned, which corresponds to 44% of the burnt area. The remaining 56% were pine trees. In Galicia, there are about 310,000 hectares of eucalyptus, about 434,000 hectares of pine trees and about 415,000 hectares of deciduous hardwoods. Eucalyptus and pine trees cover twice as much area as deciduous trees, but burn five times more.

So, is lyocell sustainable?

Despite its negative impact on the environment, lyocell is one of the more sustainable materials. The fabric is biodegradable because it is made of natural materials, and it is also recyclable. The danger of Lyocell lies mainly in the scale of its production. If many fashion brands start using the material to replace polyester and cotton, a lot has to be produced, a lot of forests are needed and problems with biodiversity will increase. If the quantity is kept in check, the serious consequences can be avoided.

Did you find this article interesting? Then be sure to read our article about Tencel, a type of lyocell manufactured by Lenzing.

Would you like to discover sustainable clothing made from lyocell? Take a look at our shopping guide and discover sustainable clothing in your style and within your budget, in your area!

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