Dyeing is the process of adding colour to textile products like yarns, fibres, and fabrics. Historically, the primary source of dye has been nature, colours made from plant and animal sources, but since the mid 19th century, humans have been producing artificial dyes that attain a wider range of colours, and that are more resistant to washing and overall use. However, synthetic dyes have harmful effects on both human beings and the environment. They are made up of toxic chemical compounds, the largest class of which being Azo dyes, that can be very dangerous for people who are exposed to them, not only at the time of production, but when particles become detached from garments through rubbing and are transferred to the skin. Wastewater contamination too, is a huge problem with synthetic dyes. Even after wastewater has been properly treated, residual chemicals from the dyeing process continue to be present in water supplies. What is more, in developing countries such as India and China, where wastewater is not as closely regulated, untreated dye effluent is often dumped directly into important bodies of water, severely affecting humans, aquaculture, and agriculture.
The solution is to revert back to the use of natural dyes. They do not have the same toxic residues as artificial dyes, they can be grown organically, and they are carbon neutral. Additionally, their use is beneficial at an artisanal level – rekindling centuries old cultures and skills provides work in areas of rural unemployment, directly improving the livelihoods of craftspeople and their communities. The traditional process forms part of an ecosystem, with wastewaters being used to water and fertilise the land, providing nutrients for microorganisms. Additionally, a range of eco-responsible polyester dyes has been developed for digital printing on polyester blended fabrics. More companies are starting to practice good business and natural dyes, or more efficient treatment processes, are more frequently used. This is due, in part, to the fact that environmental and subsequent health effects of synthetic dyes are increasingly becoming subject to scientific scrutiny, which in turn, has seen the imposition of legislations controlling their release into the environment.
The problem, as mentioned previously, is that the majority of garment production and dyeing takes place in developing countries where, often, health and safety protocols are not well enforced. Here, the use of substances such as AZO dyes, whose presence in products likely to come into close contact with skin has been banned by the EU, goes unregulated. A 2012 Greenpeace study found traces of such substances in items of clothing from 20 global brands sold across 29 countries, including two products from Zara.