To make bamboo fibers, the bamboo undergoes a process that uses carbon disulfide and sodium hydroxide. (I'm no chemist so I had to look these up.) Carbon disulfide, which is used to break down bamboo and many forms of viscose and rayon, has been linked to nerve damage and Parkinsonism. Sodium hydroxide is the chemical name for lye. Lye can cause burns and is classified as a hazardous, corrosive material. And, just for fun, Wikipedia defines corrosive material as: a liquid or solid that causes full thickness destruction of human skin at the site of contact within a specified period of time. Gross, right?
So, what to do? I really enjoy knitting with bamboo yarn and bamboo yarn blends. I appreciate the feel of it -- it is smooth, soft, and kind of fluffy. I also enjoy wearing the sweater I knit with bamboo and soy yarn. But I enjoy this material a lot less if my yarn is toxic to people and the environment. Until I can locate organic bamboo yarn, I won't be buying any new skeins. For now, I will be using the bamboo yarn in my stash.