It is nearly spring in the UK! As the early bulbs start to flower in the local parks, viscose and rayon challis is out in force in fabric shops. After the beginner “sew everything in cotton” stage you have probably moved on to this stuff or at least seen it for sale. On the surface it seems great – who doesn’t want a breathable fabric with lots of drape that comes in a zillion prints? And a lot cheaper than silk!
But as usual there is a flip side on the sustainability picture. There are a lot of shock horror type stories associated with viscose (and general textile) production such as the Guardian article here, so I thought it would be an idea to see where the land lies on this. Turns out the viscose fibre family is not simple – I’ve already spent hours on reading and still only come up with a high level view. But hopefully this post will give you a small intro to a big topic and give you some things to think about. Let me start with some definitions:
Viscose, modal, cupro, lyocell all belong to the family of “regenerated cellulose fibre” or “cellulosics”.
• Viscose can also be called rayon according to the US Federal Trade Commission
• The trademark name for lyocell is Tencel.
• EU legislation gives each fabric a slightly different definition depending on the processing, but ultimately the raw inputs are the same – plants (mostly trees).
Regenerated cellulose – a natural man made fibre.
Sounds contradictory but makes sense. Cellulose is natural as it is a carbohydrate within plants that gives them their stiffness and strength. But cellulose needs to be first extracted. So it is turned firstly into a pulp (known as Dissolving Wood Pulp, or DWP) and then spun into a fibre (i.e. regenerated / made made).
Viscose fabric is >91-95% cellulose. Did you know that cellulose is in almost everything? Over the past 200 years the uses for cellulose has massively increased – paper is made from cellulose, toothpaste and washing powder fillers use cellulose and so do baby wipes.
The production process at a glance.
This infographic is my interpretation of the production process. But there are variations in chemicals etc. depending on who makes it. Also I am no chemist so if any of you know better than me are please tell me if I have gone wrong!
Who makes this?
There are a limited number of viscose producers operating in limited geographies, with 5 companies collectively producing >50% of global DWP production. Whilst there are other sources of DWP, at this moment cellulose is primarily sourced from hardwood forests and plantations (source: Water Footprint Network). The company Sappi for example produces around 20% of the world’s DWP, and states on its website that it uses eucalyptus, aspen and maple trees from sustainably managed forests and plantations.
Environmental considerations with production.
1. All cellulosics – viscose, Tencel, modal, cupro – need trees.
The CanopyStyle campaign run by Canopy Planet (a not for profit organization focused on forest protection) emphasises sustainable tree sourcing, and there are some pretty depressing statistics:
- 70% of the tree is wasted in the production of cellulose.
- >150 million trees are logged each year for textile purposes. Deforestation is happening in Indonesia, Canada’s Boreal and temperate rainforests and the Amazon for cellulose production.
Whilst I believe Canopy Planet is likely to be a reputable source given their high profile I still feel uninformed on the scale of the problem. For example, I wasn’t able to find how much deforestation is attributable to viscose production. And also how much is 150 million trees? According to the Rainforest Network, forest density can vary between 50,000 to 100,000 trees per square km. This means that every year, 1500 – 3000 square km is being used for viscose. When this is compared to the general figure of 70,000 square kms of forest being lost each year from timber harvesting, agriculture and wildfire spread (source: Intactforests.org) it suggests we have better things to worry about than trees for viscose. Another thing I don’t have an answer to is why trees are still being used when it could really be any other plant (cotton linters, bamboo etc. I’ll look into bamboo another day).
2. Viscose production is chemically intensive, many of which are hazardous to health. The chemical processing also results in emissions and effluents.
The consultancy Made-By has made an environmental benchmark for fibres, which is graded from A (good) to E (bad). Most of the viscoses are E, modal is D, and lyocell is B – not great is it! For reference, the criteria includes emissions, human and environmental toxicity, and land / water / energy use. I suspect this is largely due to the chemicals in use and the difficulty with disposing of them. For example, for wood pulp to be dissolved (step 4 on the infographic), the pulp needs to be treated with carbon disulphide and then dissolved by adding sodium hydroxide. You might know this as caustic soda or lye. Both are toxic chemicals and hydrogen sulphide (rotten egg gas smell) is generated as a by product. Note – there are many different ways to assess fibre sustainability and this is one of many methodologies done by many parties.
But progress is being made.
Whilst cellulosics make up only around 7% of the world’s fibre production for textiles (the majority is cotton and polyester), this is set to increase in the coming years. Fortunately, seeing that there is only a limited set players in the viscose supply chain (the USA is the largest producer of DWP and trees for DWP?) you would hope that the push for sustainable tree sourcing would not be insurmountable. Canopy Style has made headway into this after 4 years of campaigning:
• 125 brands / designers have committed to eliminating endangered forests from their sourcing.
• 11 viscose producers representing 70% market share now have endangered forest sourcing policies.
Is it enough?
Rainforest Alliance audits of supply chains using Canopy Style criteria show 25% of the entire viscose supply chain is now at “low risk” … but that means 75% that is still not low risk! Of course it is better than 0% but as with so many other environmental initiatives I would need to do a lot more reading to have a view on how much is too little too late.
The sewist perspective
Personally I am not a great fan of viscose despite the positive aspects (drapey, smooth, breathable, not expensive etc). The wrinkling and slippery-ness is mostly too annoying for me to deal with – but after looking into this I will be thinking triply hard as to whether I even want to buy it. Given the difficulty with fashion companies being able to unpick their full supply chain there is little hope for the average consumer finding information on where their fabric comes from. Particularly if a fabric store sells overstock which could have come from any factory. On that happy note, I’ll leave you with a picture of one of the viscoses that did the rounds in all the shops last year (which I turned into a Sew Over It kimono).