Organic Clothing Blog recently brought our attention to the important distinction between bamboo, the miracle plant, and bamboo fiber, the more troublesome fabric. While bamboo is indisputably one of the world’s most sustainable and eco-friendly grass plants, the clothing fiber is not easy to produce from the raw grass, nor apparently as sustainable. Manufacturing the fiber into a usable fabric appears to be wrought with environmentally concerning effects.
Two well know processes exist for producing regenerated bamboo fiber:
1) Chemical Processing: Sodium hydroxide (NaOH- also known as caustic soda or lye) is used to ‘cook’ the fiber into a form of regenerated cellulose fiber
carbon disulfide is used for hydrolysis alkalization combined with multi phase
bleaching. This process produces a fiber also known as bamboo rayon or modal.
Chemical processing is the most popular bamboo fiber regeneration process.
2) Mechanical Processing: In mechanical transformation, machines are used to crush the woody parts of the bamboo plant; natural enzymes are then used to break the bamboo into a mushy mass at which point the individual fibers are combed out and spun into a yarn. This is similar to the process used to make linen. As such, the end product in this process is also known as bamboo linen. This process is much less popular than chemical, primarily because it is much more labor intensive and costly.
Both processes present environmental hazards and harmful health effects. As for the chemicals (the more widespread process), breathing in carbon disulfide is known to cause tiredness, headache and nerve damage among the exposed. At factory plants it is also associated with neural disorders among rayon manufacturers.
Low levels of exposure to sodium hydroxide is also known to cause irritation of the eyes and skin. As a strong alkaline base in its crystalline form, caustic soda (NaOH) is one of the major ingredients of Drano. These same chemicals are used not only for bamboo, but in standard rayon processing from wood or cotton waste byproducts.
Because of the health risks posed by these chemicals, coupled with the negative environmental impacts in surrounding factory plants, bamboo manufacturing, like other regenerated fibers produced using hydrolysis alkalization, is not considered eco-friendly, nor sustainable. However, important to note is that some companies ARE producing bamboo organically, using processing that do not involve bleaching.
Yet, what is the alternative? When assessing environmental impacts, we must always weigh the alternatives, one of which is traditional cotton. In the case of cotton, while in some cases the processing may be less chemical intensive (although not always) the growing is one of the most environmentally destructive crops in the world both in terms of water and pesticide use.
In addition, it appears there are some organic bamboo processing pioneers out there and more are on the way. I am certain that it is only a question of time before we develop environmentally friendly processes to transform the pulp into fine fibers. Consider the green progress made in household cleaning, lawn fertilizer and pesticide products. It is only a question of time before we discover greener methods for bamboo processing, too.
Additional advantages of Bamboo: Bamboo fabric is very soft and can be worn directly next to the skin. Many people who experience allergic reactions to other natural fibers, such as wool or hemp, do not complain of this issue with bamboo. The fiber is naturally smooth and round without chemical treatment, meaning that there are no sharp spurs to irritate the skin. (Source: Wise Geek.com)
More on Bamboo (wisegeek.com): Bamboo fiber resembles cotton in its unspun form, a puffball of light, airy fibers.
Photo Credit: Organic Clothing Blog