Other denim dangers

Most jeans, including many made from organic cotton, are dyed using synthetic indigo—a petroleum derivative—to achieve their iconic blue coloring. Creating the synthetic indigo and then turning it into a dye requires the use of hazardous chemicals including hydrogen cyanide and heavy metals.[18] Some organic jean makers use a "low impact dye" that requires the same toxic chemicals, but it's absorbed better and a bleaching agent such as hydrogen peroxide is used in place of chlorine.