Is All Rayon "Green"?
Q: I’ve heard that rayon is an environmentally responsible fiber, but I’m confused. I see all of these terms on apparel and home fashion labels -- viscose, rayon, tencel, bamboo, lyocell – are they all the same and are they equally environmentally responsible?
A: Excellent question! With all of the terms used to describe rayon, no wonder consumers are confused! Rayon was the first manufactured fiber, commercially introduced as “artificial silk” in the early 1900s. As a regenerated cellulosic fiber, its raw material is cellulosic and therefore comes from a renewable base material. However, not all manufacturing techniques for rayon are equal from an environmental perspective. There are three types of manufacturing techniques or generations of regenerated cellulosic fibers:
1. Viscose process (first generation) for rayon: in this process, cellulose (wood pulp) is treated with caustic soda and carbon disulfide. Although chemicals do not remain as a residue on the fiber, disposing of the chemicals used in the processing can create pollution in wastewater.
2. High Wet Modulus (HWM) process (second generation) for rayon: HWM process increases the wet strength of rayon. Similar to the viscose process, disposing of chemicals used in the process can be polluting.
3. Lyocell (third generation): according to the Federal Trade Commission, lyocell is the generic name for a “cellulose fiber obtained by an organic solvent spinning process” and is considered a sub-class of rayon (Federal Trade Commission, 1996). The lyocell process reuses up to 99.8% of the solvent and remaining emissions are broken down.
Rayon (viscose and HWM) and lyocell are produced from renewable cellulosic plants such as beech trees, pine trees, and bamboo. All are bio-degradable; although all may not be made from plants harvested using environmentally responsible ways. Lenzing Viscose® and Lenzing Modal® HWM rayon are made from sustainably harvested beech trees certified by PEFC (Programme for the Endorsement of Forest Certification).
The lyocell process is the most environmentally responsible processing method among the processes for regenerated cellulosic fibers. This has sometimes caused confusion for fashion brands/companies and consumers. For example, in 2003 bamboo was introduced as an environmentally responsible fiber because the cellulose base (bamboo) was renewable. However, the viscose processing method was used. The Federal Trade Commission now requires that if the viscose method is used it must be labeled as rayon made from bamboo.
Lenzing’s Tencel® lyocell is one of the most common lyocell fibers available. Not only is Tencel® lyocell made from eucalyptus grown on land unsuitable for food crops, the plants require less water than cotton, non-toxic solvents are use, the filament fibers use a water-based bath, and solvents are washed from the fiber and re-used. In addition, Tencel® lyocell is more odor-resistant (prevents the growth of bacteria which cases odors) than viscose rayon, HWM rayon, or cotton. Therefore, products made with Tencel® lyocell do not need to be washed as often as those made from these other fibers.
So, if you are looking for an environmentally responsible rayon fiber – look for one labeled as lyocell or Tencel® lyocell!