Think that pure white, organic cotton tee shirt is environmentally friendly? Hm, most likely not. People might jump to the bleaching chemicals and yes, those are toxic and can be polluting. But another problem is the huge amounts of energy required to bleach out the natural color of cotton. But a new study, published this week in the Journal of Industrial & Engineering Chemistry Resarch, has a solution.
Currently the cotton industry requires bleaching the natural cotton fiber with hydrogen peroxide at extremely high temperatures. We've grown to love bright whites but this process compromises the quality of the cotton material. And when we realize that there are 7.3 billion pounds of cotton produced in just the U.S. this process uses too much energy for it to be sustainable.
Scientists focused on lowering the required high temperatures by using a compound that can bring the bleaching temp down to 140°C from 200°C. Their hope is that the 60° drop will result in a process that needs less than half the energy needed in the commercial technique used today. Additionally it reduces the wastewater. And as an added bonus, the resulting fiber is thicker and in better shape.
So if you are looking for a pretty dramatic improvement in energy used during a bleaching process check out their study here. But on the global scale we still need to deal with the amounts of water required to grow cotton in the first place. According to the World Wildlife Fund it takes 5,000 gallons of water to grow enough cotton to make one tee shirt and a pair of jeans. We still need a solution for that.