Chemical processing of wool: Sustainability considerations

Raw wool fibers contain fat, suint, plant material and minerals. It is necessary to remove these from wool by scouring with a combination of detergents, wetting agents and emulsifiers before further processing. Dyeing and finishing of wool fibers is necessary for their application in apparel and also in interior, automotive, smart and technical textiles. Some of the detergents and auxiliaries used in scouring are eco-toxic and some of them are endocrine disruptors. In many countries, wool scouring and dyeing effluents cannot be discharged to watercourses without further treatment by removing color and toxic components. Wool fibers can be given chemical treatments to make them stain-resistant, flame retardant, shrink-resistant, photo-stable and resistant to insect attack. Some of the chemicals under current practice to achieve these functionalities in wool are not eco-friendly and their discharge to water course is limited to the consent limit set by environment agencies. Environmental impact assessment of raw wool production is well studied but to our knowledge no comprehensive study has been carried out around the environmental impact of chemical processing of wool. Like those of other fiber types, the wool textile industries are under intense consumer as well as stakeholder scrutiny. Accreditation schemes now exist to provide reassurance to modern consumers, who want to see that not only are the marketed products safe but also that they are processed sustainably under ethically and environmentally acceptable conditions. Several alternatives to improve the environmental credentials of various chemical processes used for wool will be discussed.