• Dyes are hard to biodegrade
• Some pass into rivers and streams – the biggest problem is dyes used for cotton
• This is a major public issue in the Severn Trent region
• There are suggestions that colour in river water could be solved by better mixing – but dye manufacturers say this will not happen in the near future
• Another solution to colour in rivers is to treat and recycle waste water on site.
• Some contain heavy metals – copper, zinc, chromium
• A large amount of energy is used
• Dye houses can become ‘greener’ by cutting water use, reusing water from dyeing, rinsing, cooling, recovering raw materials and managing effluent
• Pesticide control (from residues in textile waste water) is a major issue in Germany – and is expected to become important in the UK
• The use of formaldehyde as a crease resistant
• Air emissions from coating processes
• Natural dyes are questioned because of the sustainability of plantations, expense, natural toxins, length of dye time, disposal and the need to fix them with use of heavy metals