The latest international development of a more environmentally friendly denim blue dyeing method reduces the environmental impact by up to 92%

Chinanews.comBEIJING, Feb. 28 (Reporter Sun Zifa) Springer Nature's academic journal Nature Communications recently published a sustainability study that found that researchers have developed a new method of dyeing denim blue, which may reduce the environmental and social impact of producing blue denim. The authors note that the new method could reduce the environmental impact of blue denim dyeing by up to 92 percent and prevent denim factory workers from being exposed to harmful chemicals at a modest cost.

According to the paper, the production of blue denim is a multi-billion dollar industry, and the dye currently used is indigo, which is currently the only molecule that produces the unique color of blue denim. This process emits a lot of carbon dioxide and uses a lot of toxic chemicals, which leads to environmental pollution and harms the health of textile workers and local communities. Indican is a colorless precursor to indigo and is a more environmentally friendly denim dye because it does not use toxic chemicals and can be turned into indigo directly on spinning. However, the application of this method requires energy-producing indigoside technology.

Co-corresponding authors Ditte Hededam Welner and Katrine Qvortrup of the Technical University of Denmark, together with colleagues and collaborators, engineered an improved version of indolesyltransferase, which was found in the indigo-producing plant Polygonum tinctorium, to economically produce indigoside on an industrial scale. They also demonstrated economically viable, low-harm dyeing processes that turn indigo into indigo and dye denim, one of which uses enzymes and a light-driven approach. For the latter, different light sources have been shown to be useful for dyeing denim in a solution with cloth, including energy-efficient LEDs, natural light, and even a household light bulb.

According to the authors, light-driven dyeing is expected to reduce the environmental impact of blue denim dyeing by 73 percent, while enzymatic dyeing can reduce it by 92 percent. According to market analysis, 4 billion jeans are traded annually, and these methods could reduce the generation of toxic waste and reduce global carbon dioxide emissions by 3.5 million tons per year.

They concluded that the newly developed eco-friendly denim blue dyeing method, which could reduce environmental impact or promote local production in the Western denim market, could improve supply chain transparency and sustainability in the textile industry.