Viscose appears on our clothing labels as a material. But in fact, it’s a way of processing a natural material, and a process that’s not all that clean!
Viscose : an synthetic material of natural origin
Viscose is a material derived from wood, which has its advantages but also its drawbacks.
Derived from wood
It’s referred to as a natural material, because it is yielded from a natural fibre. Because viscose is derived from wood cellulose (bamboo, maize, soya, beech or eucalyptus). The term “viscose” comes from the way in which the fibre is made, a viscous organic liquid used to make both rayon and cellophane. Viscose was originally called synthetic silk, because the Frenchman who invented the process, Count Hilaire de Chardonnet, was looking to yield a material close to silk, which was very fashionable at the time (1884) but costly. Viscose met with immediate success. As for the term “rayon”, it appeared in 1924. It was not until 1938 that viscose started to come up against competition from synthetic fibres derived from petrochemical oil.
To this day, viscose is very commonly used in the textile industry. It is estimated that worldwide, 99 million tons of wood pulp are used to produce viscose every year!
An “easy” material
The resulting synthetic fibres – in addition to their low cost – yield a fabric that hangs nicely, is shiny, soft to the touch, fine, sometimes form-fitting and pleasant to wear. In addition, viscose fabrics are very hardwearing and take colour well. They stand up to laundering over and over better than natural fibres, which can fade.
However, viscose also has its limits. Anyone who has tried to launder a garment made from non-prewashed viscose fabric will have found it out the hard way: viscose can shrink when laundered, gets creased easily and deteriorates when exposed to light. In addition, its fibres don’t absorb moisture and don’t retain heat. This means that they are unsuitable for winter clothes and performance sportswear.
A production process that’s chemical, polluting and resource-guzzling
Presented as biodegradable, sustainable, eco-friendly alternatives to cotton and polyester due to their natural origin, viscose fabrics are promising. However, their production process has an impact on the environment.
They promote deforestation
To supply the wood needed to produce these synthetic materials (5 million tons), 70 million trees are felled every year just to meet demand from the textile trade. Because it takes around 1 kg of natural fibres to yield 400 g of regenerated viscose fibres. In addition, thousands of hectares of tropical forest are cleared to plant trees used specifically for rayon production. Furthermore, growers practise monoculture, which destroys biodiversity since it always draws the same nutrients from the soil and depletes it. This means that growers have to use pesticides and fertilisers.
A polluting process
The viscose production process requires a great deal of water. It takes between 400 and 11,000 litres of water to produce 1 kg of viscose. Wood pulp is dissolved in a caustic soda bath to yield a fluffy mass. This mass is mixed with (toxic, inflammable) carbon disulphide. It then turns into a paste. This paste is pulled into threads. Lastly, the resulting filaments are cooled in a sulphate and sulphuric acid bath which sets the fibres prior to weaving. In developing countries where viscose is produced there is no reprocessing of chemical waste, meaning that it gets discharged into the natural environment and rivers, and pollutes ecosystems.
In addition, these harsh chemicals partly remain in fabrics made out of viscose, despite the processing stages (dyeing, printing, trims, washing…). So then, viscose is toxic for the consumer after having been toxic for the workers who produced it.
There are ethically-sound and eco-friendly types of viscose
Despite this polluting production process, viscose is still widely used, including by fashion brands that claim to be ethically sound and environmentally responsible.
From sustainable forests
Some types of viscose are made from bamboo or eucalyptus pulp that comes from sustainably-managed forests, which hold the PEFE-FSE or FSC certificate. This certifies that the source of the plant-based material is respectful of the environment and the workforce. Stella McCartney uses viscose from sustainable forests in Sweden.
A cleaner process
The Changing Markets foundation takes the view that it is not impossible to design cleaner viscose. The organisation has put together a roadmap aimed at companies in the sector, shining a light on the various ways of making the supply chain safer and respectful of people and the planet.
More and more fast fashion chains are going down this route, by signing up to this roadmap.
Lyocell – clean viscose
Viscose is increasingly being produced via the Lyocell (or Tencel®) process. This uses N-Methylmorpholine N-oxide (NMMO) as a solvent, whose stand-out feature is recyclability. This means that the process is almost a closed circuit. In addition, the water is fed back in and the plants that provide the cellulose are from sustainably-managed forests. Lastly, Lyocell fibres are biodegradable.
A survey published on 10 January 2019, commissioned by the Changing Markets foundation and the Clean Clothes Campaign from the Ipsos MORI agency, revealed that 75% of French consumers think clothing brands should provide information on their environmental commitments, and that 72% of French respondents are in favour of having clothing brands provide information on their viscose producers and the impact that they have on the environment. Despite the efforts made, we still have a long way to go!