Sustainable dyeing processes are revolutionising the textile industry

According to Play and Plug, dyeing cotton is a particularly water-intensive process. Picture: Cottonbro/Pexels

According to Play and Plug, dyeing cotton is a particularly water-intensive process. Picture: Cottonbro/Pexels

Published Aug 25, 2021

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Fashion trends might be seasonal but the by-products from creating those on-trend outfits you rock have a far greater impact on the environment than on your Instagram feed.

While there’s been a rapid movement towards sustainable fashion, it’s taken the textile dyeing industry longer to move with the times.

When the environmental organisation Greenpeace released photos of abnormally green- and magenta-coloured rivers in India and China in 2011, it was a rude awakening for the fashion industry.

The polluted waters were due to the toxic chemicals released from nearby textile factories, which were not only changing the rivers’ colours, but depleting these countries’ often limited water supplies.

According to Play and Plug, dyeing cotton is a particularly water-intensive process. It is estimated that dyeing and finishing can use around 125 litres of water per kilogram of cotton fibre.

They have reported that a large amount of potentially toxic chemicals are used to dye clothing, but there's a lack of knowledge and transparency about their properties in relation to human and environmental health.

Even though the progress is slow, new dyeing processes and technology - such as pre-treated cotton and creating natural pigments from microbes - are being explored to accelerate change.

One might wonder why textile companies are not using natural dyes, which are far less toxic than synthetic dyes. This is because the process still requires agricultural land and pesticides for the plants that make up the dyes.

However, laboratories have already started working on technology to create colour for clothing by using bacteria.

A London-based lab, Faber Futures, uses the pigment-producing bacteria, streptomyces coelicolor, to create a large range of colours that can be used to colour both synthetic and natural fibres.

Streptomyces coelicolor is an easy bacteria to grow and is harmless to humans and the environment. The production and dye processes require 500 times less water than traditional dyeing and need zero colour-fixer.

Faber Futures founder and materials designer Natsai Audrey Chieza started working with the micro-organism in 2011.

Another company using pigment-producing bacteria is Living Colour, which is based in the Netherlands.

In 2020 they collaborated with sports brand Puma to create the first-ever bacterial-dyed sports collection.

According to GBC College English  around 11 000 litres of water are used from beginning to end for a single pair of jeans during the manufacturing process of denim.

Indigo blue, the colour used to give denim its colour, is made with toxic ingredients. Conventional indigo requires dangerous chemicals – like benzene, formaldehyde, and sodamide – and carbon-emitting petroleum in production.

Huue has created a biosynthetic indigo blue for the denim industry. Biosynthetic indigo has five times less toxicity potential than chemical sources, while being just as effective, and easy for jeans makers to use.

ColorZen, a provider of cotton dyeing technology solutions, won an award in the Innovation Competition at the 2018 Copenhagen Fashion Summit for their role in sustainable fashion.

They use a patented technology that pre-treats cotton before it is spun. This pretreatment process makes the dyeing process faster, reduces water usage and uses less energy and 90% fewer chemicals than would otherwise be needed for the effective dyeing of cotton.