How sustainable is wool?

How sustainable is wool

Wool is a natural material and we could easily assume that’s enough to be sustainable.

Wool used to be one of the most common materials, but with the advent of synthetic fibres and the omnipresence of cotton, both the worldwide production and consumption (at least for apparel) has decreased. However, we still like a lovely warm woollen jumper or a merino coat, and sewing with wool fabrics is great, isn’t it? Although in general wool is considered a more sustainable fibre or fabric, there are a few things you need to know so you can make informed decisions.

Before we continue, a bit of geekiness: although cashmere, Angora and mohair are often considered wools, they are actually yarns made out of the hair of cashmere goats, Angora rabbits and Angora goats respectively. So they will be covered in a future post.

(Sheep) Wool

Photo by Ken Hammond, via Wikimedia

What is it?

Sheep wool is the most common animal fibre used today and it has been part of the human way of life for hundreds of years. Until cotton was introduced in the Western world on an industrial scale, sheep breeding for wool and wool cloth making have been a staple of the major European economies, like Britain, Flanders, Germany, Italy (to name but a few). Currently, the largest wool producers in the world are Australia, followed by China, America and New Zeeland.

Wool carding
Wool carding Photo by Libby A. Baker via Wikimedia

Wool is the coat sheared from various breeds of sheep and it differentiates from animal hair (such as Angora or Cashmere) through several qualities: it is crimped, it is elastic, and it grows in staples (clusters). Spinning (turning wool fibre into yarn) is easier due to these qualities because individual fibres attach to each other and allow the formation of long, continuous thread. Because of the crimp, wool fabrics have greater bulk than other textiles, and they hold air, which allows the fabric to retain heat. The crimp refers to the fineness of the wool fibres. A fine wool like Merino may have up to 100 crimps per inch, while the coarser wools like karakul may have as few as one or two.

The sustainability angle:

In general, wool is considered a reasonably sustainable fibre, because it is natural and renewable (can be harvested regularly without harming the animal). It is also recyclable and biodegradable. However, wool fabric production it is not 100% without issues.

These are the main ones:

• Raising the sheep themselves. The more sheep located on a certain piece of land, the greater the risk of over-grazing, which can lead to desertification. Land used for pastures could be used for food crops instead, so this is also raised as a concern. [EDIT] Since posting this, it has been highlighted to me that the above statement can be misconstrued to refer to Britain, which is nott he case, as sheep often graze on land that is so poor, and where the weather is so extreme, that no crops of any sort can be grown.
• Water consumption (by sheep themselves) and that used during wool processing. According to Sustainable Apparel Coalition’s Higg Index. the water intensity associated with wool can be only slightly better than cotton. An estimated two-thirds of the weight of raw wool is grease, skin flakes, dried sweat, dirt and plant matter, which needs to be eliminated through a process called scouring. Scouring can use lots of water, detergents and solvents, and produce polluted wastewater. However, it is worth noting that, with all the different breeds of sheep in different colours, undyed wool yarn is now very common, and some of the major small mills in the UK use organic dyes.


• Use of chemicals during sheep rearing (pesticides to protect the pastures and insecticides for the sheep themselves), production of wool, yarns and fabrics. Chemicals used in the manufacturing of wool fabrics do not score very high on the Higgs Index and increasingly, there have been calls to reduce these substances in the supply chain though compliance schemes.

Author: Thomas Quine, via Wikimedia

Also, ethical aspects come into play. Mulesing is a practice in industrial sheep rearing where skin is removed from around the breech area of sheep to prevent the very harmful flystrike. Mulesing became a widespread practice because infections caused by flystrike can lead to serious harm and even kill the sheep. Animal rights organisations have denounced this practice as unacceptable and have pushed for retailers and manufacturers to boycott wool from countries that do not agree to ban it. In the UK, the British Retail Consortium and its members have taken a tough stance against this practice. You can read more about it here. [EDIT] Just to reassure you, mulesing is not being practised in Britain and there are current projects in Australia and New Zealand to develop sheep that are less likely to suffer flystrike and to change management practices so that mulesing is not necessary.

The good news is that there is a significant movement to produce wool organically, and organic wool yarns and cloth are more and more widely available. But, as with organic cotton, it’s not very easy to produce wool in such a way as to acquire certification. Feed must be organic, no pesticides can be used, sheep cannot be chemically treated against parasites, good cultural and management practices of livestock must be used. And it’s worth noting that ‘organic’ only refers to the production of wool, not the actual fabric that is made out of the wool. However, the GOTS standard that we mentioned in relation to the organic cotton is also valid for wool, so fabric manufacturers can get certified.

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Coloured wool
Author: AgainErick, via Wikimedia

Another good thing about wool is that it can be easily recycled, either by unravelling the knitted garments and reusing the yarn for new items, or by shredding, carding and spinning recycled yarn. Because the qualities of recycled wool fibre are not as high as virgin wool, in order to maintain the quality of the final fabric, it is necessary to mix them with virgin wool, cotton or silk. Lower quality wool can be used for non-apparel products.

Alpaca, Llama, Vicuña  & Guanaco

What are they?

They are all members of the Camelid family (related to camels) that live in the heights of the Andes in South America. Their wool has been used by the Incas and other local populations for hundreds of years, because it is fine, warm and light.

A flock of Alpacas
A flock of Alpacas Credit: Philippe Lavoie, via Wikimedia

Alpacas are the most common, as they are being bred outside their native regions, especially in the US, Canada, Australia, New Zealand, UK, and numerous other places, for their high quality wool. They are the domesticated cousin of the vicunas (see below) and were especially bred for their wool, very much appreciated by Inca royalty. Although quite similar to their better known domestic cousins la llamas (of the Disney Emperor’s New Groove fame), alpacas are smaller, daintier and produce three times more wool than a llama. Llamas were mostly bred as pack animals and sometimes they are used to ‘guard’ the herds of alpacas.

Alpacas were first brought into the New World by the Spanish, but early attempts to make cloth out of it were unsuccessful, until a new method was discovered in Bradford in the 1830s. Bradford thus became the worldwide centre for alpaca cloth production.

Vicuna is the wild cousin of the alpaca and produces the finest wool in the world, but only about 0.5 kg from one animal a year. Because of intensive hunting (they are very fast and it was easier to sheer them dead than alive), vicunas populations were declining, so in the ’70s, hunting and exports of wool were banned. However, since then, due to conservation efforts, the populations have increased significantly and since 1993, the ban on wool was lifted. The Peruvian government has a special labelling system that certifies that the wool comes from a vicuna that was caught, sheered and released through traditional methods (a communal activity called cacchu), once every two years. The profits from the wool go back to the local communities. But vicunas are still prone to poaching and loss of habitat.

Source: Vera & Jean-Christophe on Wikimedia

Guanaco is a camelid native to South America, related to alpaca and vicuna. It can be found mostly in Argentina’s pampas and in Chile and is also consider threatened, especially because of loss of pasture and loss of habitat. Guanacos are the parent species of the domesticated llama. Guanaco fibre is particularly prized for its soft, warm feel and is found in luxury fabric. The guanaco’s soft wool is valued second only to that of the vicuña. Like their domestic descendant, the llama, the guanaco is double coated with a coarse guard hair and soft undercoat, which is about 16-18 microns in diameter and comparable to the best cashmere.


The sustainable angle

Spindle with alpaca wool
Spindle with alpaca wool Author: Peter van der Sluijs via Wikimedia

All of the above fibres are considered more sustainable than sheep wool, mainly because they do not contain lanolin (the greasy substance sheep wool is covered in and which needs to be removed by chemical treatments). Also, being part of the camel family, alpacas, vicunas and guanacos do not have a split hoof, but padded feet, and this is believed to be better for the pastures they graze on. Also, the fact that they cut the vegetation they eat, instead of pulling it from the root is more gentle on their food sources. Whether collected from farmed animals or gathered from the wild animals, the alpaca, vicuna and guanaco fibres very often provide incomes for local communities, who still process the wool using traditional methods and often making hand-made items that are sold through cooperatives to European and American markets. So they have a strong ethical and fair trade component. There are even alpacas being raised in the UK, read more on the British Alpaca society website. The only issues I could find in my research is the potential poached provenance for vicuna and guanaco, but through the care of the Peruvian government and International conservation organisations, less animals are being hunted and killed for their wool nowadays.


The good news is that there are definitely options for sustainable yarn and fabrics, as there are small-scale farmers, spinners, dyers and weavers that can supply fibres with more concern for animal welfare, as well as supporting local communities and protecting the environment. More information on British wool in general here.

Spinning wool by hand
Spinning wool by hand Author: David Wilmot from Wimbledon, United Kingdom, via Wikimedia

Wool is a fantastic material to use, because it is warm, comfortable, insulating for both heat and cold, absorbs perspiration, has natural mildew and mould resistance and many other great qualities. So I for one will be looking more and more to source wool fabrics that are produced locally in Britain from wool processed sustainably and where organic or plant dyes are used. Maybe, in the long run, this might encourage mainstream fabric companies to turn away from chemically dyed, mulesed merino, and produce more sustainably overall.




  1. 25 February 2015 / 11:07 AM

    Excellent post!

    I’m thrilled British wool is having a resurgence. Yes, it still has a footprint, but as you mention, in the UK it is generally grown on marginal land and where sheep are on good pasture (e.g. in the South West), the fleece is a by-product of the dairy industry. Also, in the UK wool allows us to shrink the supply chain. We have re-discovered the joy and benefits of locally sourced food and wool allows us to do the same with our clothes to some extent. It provides real and local jobs for people, which is an integral part of the sustainability equation. If only we could bring more large scale clothes production (weaving and stitching) back to the UK too.

    Another part of the environmental equation is that in colder climates, like the UK, woollen clothes are an efficient choice. Woollen sweaters, trousers, skirts… are much warmer than acrylic or polyester garments and allow us to turn the heating off/down. The Higgs Index is useful for exploring the credentials of fibres and fabrics, but we shouldn’t ignore the implications of how we use, or should be using, clothes.

    (PS – yes, I’m a big fan of wool, and yes, I even unravel homemade knits to reknit the yarn!)

    • Alex
      25 February 2015 / 11:55 AM

      Thanks, Meg! I was a bit worried this might be controversial, as I am not a knitter myself, so don’t really know the ins and outs. But I have unravelled old jumpers galore back home in Romania, when I was growing up, it was really good fun too :). My challenge now is to find wool fabric that is sustainable and won’t break the bank :).

  2. 25 February 2015 / 3:35 PM

    Thanks for posting this Alex. I’m a knitter, but no time to read it at the moment as running for all sorts of deadlines. I will however come back and read through – just wanted to let you know it was appreciated while the post was reasonably fresh.

    • Alex
      26 February 2015 / 5:02 PM

      So glad you found it interesting! I write these posts because I find it interesting, but I am a massive geek, so really glad to know other people find it interesting too.

  3. 26 February 2015 / 12:58 PM

    Thanks for the very very interesting post! And YAY WOOL! 😀

    • Alex
      26 February 2015 / 5:01 PM

      Thanks Coralie! I only wish finding sustainable wool fabrics was as easy as the yarn! You lucky knitters!! 🙂

  4. 26 February 2015 / 5:55 PM

    I am really enjoying reading your sustainable Tuesday posts. I’m learning so much. Thanks for taking time to write these up! Nee x

  5. 10 March 2015 / 1:58 PM

    Interesting post – I’m a wool fan (and a knitter) so I lean towards wool and other natural fibres in a big way.

    Just to muddy the water a bit more about sheep. Upland sheep farming does make use of marginal land for agriculture in the UK. However, the consequence of sheep grazing in these areas affects the tree cover and the whole of those habitats/ecosystems, influencing flooding downstream and the number and type of bird species that succeed. If you want to find out more about this, then try reading George Monbiot’s book ‘Feral’ particularly the chapter ‘sheepwrecked’.

    I’m not sure if you have already written anything about this, but as well as considering the individual impact of a particular material (wool, cotton) I think we should consider the overall impact of our wardrobes. This means addressing the number of things we own/wear, rather than just which materials each item is made from.

    • Alex
      10 March 2015 / 2:35 PM

      Hi Caroline, thanks for your comment. I absolutely agree that it’s about the systemic view and whole life cycle assessment. I am doing a ‘no RTW clothes experiment’ this year, and I’ve seen a lot of other bloggers who are doing this as well, so hopefully this is an indication that at least a certain group of people are thinking about clothes and fashion in a different way.
      Personally, I am interested in learning more about the fabrics I use so I can make better choices where I can, and I thought to post my researches, which are by no means exhaustive, or claim to be an authority, in case other people might find them useful too. Usually there is no silver bullet about anything, but I at least try to avoid (when I know about it) things that might come against my own ethics. I’m by no means a green warrior and probably not doing or knowing half as much as I should, that’s why I am grateful for all opinions and pieces of info. I’ve just got a book on sustainable materials in fashion, so that will probably be very informative as well.
      Thanks for stopping by and taking the time to read my post.

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