Textile Review: The Environmental Impacts of Colouring Yarn and Fabrics

When seeking out eco-friendly clothing options, consumers often look to the source of the fiber (cotton, polyester, hemp, linen) to reduce their environmental impact. The choice of fiber is an important first step in the process. But in order to ensure that the clothing you buy is sustainable, it is also important to consider the dying process that has been used. The colour of your clothes can have a huge impact on the environment. That dress in brilliant vermilion yellow, or the trousers in midnight black, in most cases have been achieved using a cocktail of harmful chemicals, regardless of whether the fabric is natural, such as wool, linen and cotton, or derived from petrochemicals, such as polyester or nylon.

Discharge from a Textile Dying Factory in China ~ Photo Credit: Greenpeace

Discharge from a Textile Dying Factory in China ~ Photo Credit: Greenpeace

The colouring process for fibers usually involves two or three steps- bleaching, dying  and printing- all of which are known to use harmful chemicals in conventional fabrics. Bleaching is used to whiten the textiles, which enables the dyes to achieve a more brilliant colour. Bleaching is both water and energy intensive in standard processes, and includes the use of chemicals which are highly polluting if released in the the environment untreated. Dying is a highly water intensive, energy and chemical-intensive process. Dying processes are a major source of heavy metal contamination. Printing inks used to screen-print designs onto fabric can contain harmful solvents, and in some cases even lead. In major clothing manufacture countries, such as China, poor workplace safety practices mean that textile workers face serious health consequences as a result in their involvement in the colouring of textiles.

Textile worker in China ~ Photo Credit: Greenpeace

Textile worker in China ~ Photo Credit: Greenpeace

Greenpeace, through their own investigations and the Detox Fashion campaign have been shining the spotlight on the toxic impact of fashion. They have produced an excellent short documentary which sums up the environmental impact of textile processes (of which dying is a major contributor) on the world’s water supply. You can watch this short documentary here. The documentary cites some alarming statistics on the impact of textile processes on the environment in countries of manufacture. “In China alone 40% of surface water is considered polluted and 20% of the ground water used as urban drinking water is contaminated, sometimes with carcinogenic chemicals.” While textile manufacture is not the sole contributor to this situation, by exploiting lax environmental regulation in countries of manufacture the clothes we wear cause significant environmental harm in the cities and town in which they are made.

But the impacts extend far beyond the country of manufacture. “The clothes we buy in Europe, North America, Asia and elsewhere are all part of a global chain of toxic pollution. Two thirds of clothing items tested by Greenpeace contain hazardous chemicals, and when these garments are washed these hazardous chemicals are washed into rivers, lakes and seas around the world.This makes us all part of the problem. But we can also be part of the solution.” The clothing that we choose as consumers can protect or degrade the environment. The market can only profit from goods that we choose to buy. By choosing sustainably produced clothing, we can contribute to lasting change.

What are our sustainable options when it comes to colouring/dying yarns and textiles?

The sustainable options around the colour of your garments fit broadly into three categories- low-impact, natural/eco dyes, and naturally pigmented fibers.

Low impact processes utilise chemicals to achieve the desired colour of a fabric, but the most harmful chemicals have been excluded from use. Low impact process also operate on a closed loop system (where chemicals are captured and reused again and again, rather released as waste) or produce waste that is considered environmentally safe for release. With regard to the bleaching of fibers, low-impact processes are those that use hydrogen peroxide over more harmful bleaching agents, minimise the use of stabilisers (which are highly polluting agents), and biologically treat waste water before it is released into the environment. Low impact dying processes include acid dyes (ph-controlled dye baths that are slightly acidic), exhausted dye baths (so that majority of dye agents are affixed to fabric, rather than released in the waste water) and reactive dyes. Printing process that are considered low impact include the use of water-based printing inks, solvent-free inks, and digital printing processes. For a comprehensive overview of these low-impact processes, I highly recommend Sustainable Fashion & Textiles: Design Journeys by Kate Fletcher, which has helped me immensely with my research. Generally low impact processes are better suited to the large scale manufacture of clothing than natural dyes, so are used by most sustainable clothing labels. Sustainable clothing brands such as amour vert and Icebreaker state on their website that they use low-impact dyes to colour their fabrics. Companies which utilise certified-organic fabrics, such as PACT ApparelPeople Tree and 3 Fish are required to use low-impact processes in order to receive their organic certification. If you are uncertain whether a label uses low-impact dying processes, it is worth contacting them to ask them for information on their dying processes so that you can be certain of the processes that are used.

Natural dying processes utilise foodstuffs, plants and in some case insect and animal materials to colour natural fabrics. These processes have been used throughout human history and have been preserved through cultural tradition. They are best suited to handmade and small scale production, as is is difficult to achieve uniformity and they are often more labour-intensive. Colouring in this manner encourages a slow fashion approach to garment production, and enables a greater connection to the local environment. Slow designers Sasha Duerr and India Flint explore the dye potential of the local environment through the collection and experimentation with dye stuffs gathered from their local area. For comprehensive information on natural/eco-dying techniques, I highly recommend Eco Colour by India Flint. Natural dying is a lovely process to explore in your own home, and is can be a cheap option because many food scraps such as used tea bags, beetroot peelings, purple carrot skins, and used coffee grinds all have dye potential. For a basic introduction to natural dying, see my tutorial for dying an organic cotton t-shirt with used tea bags. There are also an increasing number of commercially-produced soy-based and other natural textile dyes and printing inks available on the market, which means that natural dyes are becoming increasingly accessible to larger scale manufacture. However, we are yet to see these available beyond a niche market of consumers and makers.

Tea-dyed hand-printed t-shirt by tortoise & lady grey

Tea-dyed hand-printed t-shirt by tortoise & lady grey

The final option for colouring yarn is to make use of the natural pigments already existing in the fibers. This is the most environmentally friendly option, as it eliminates any use of dyestuffs, water and energy needed to colour the yarn. This is the most restrictive in terms of colour choice, but there is a range of colours that are naturally occurring and can be used by garment designers to reduce the environmental impact of the clothing. In South America, there are a number of organically grown traditional cotton varieties that are hued in soft greens, yellows and pinks and are perfect for producing beautifully soft baby clothing that are chemical-free. Similarly, many traditional varieties of sheep, alpaca and even camel are farmed for their wool in hues of charcoal, chocolate, caramel and cream that produce beautiful knits such as this  charcoal striped knit from Icebreaker. Other natural fibers such as linen and silk look lovely undyed.

The colouring of yarn and textiles is only one part of the overall environmental impact of a garment, but it is important that this impact is not overlooked. Through my investigations over time I have found it helpful to ask suppliers and designers about the dying processes used. Sometimes you will be surprised to find that a low impact process has been used. Other times you may be disappointed to find out that this is not the case, or you may even find that the company has ignored your inquiry, but at the very least you have had the opportunity to let designers and makers know that there is consumer demand for fashion to change to low-impact processes.

As consumers, the more opportunities we have to make our ethics known, the greater impact we can have on the market. Early successes with the Detox Fashion campaign have demonstrated the impact that sustained consumer activism can have when people work together for change. But even on an individual scale, we cannot discount the impact of consumers writing to fashion labels to inquire about their processes. If nothing else, it lets companies know that we care about the issue and will change our shopping habits to support change in the market place.

Guide to Sustainable Textiles


If you enjoyed this post and learned something new, you will love my Guide to Sustainable Textiles. Covering the 15 most common textiles, this throughly researched guide will support you to make purchases in line with your ethics and commitment to sustainability.

If you want to assess the sustainability of your favourite brands, this is the guide for you.

Avaiable for only $9. Visit the Guide to Sustainable Textiles for more information and to buy.




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