To Bamboo or not to Bamboo that is the question
Bamboo Sprouting Green Myths
"Advertising is the 'wonder' in Wonder Bread." - Jef I. Richards, Professor of Advertising, University of Texas at Austin
Bamboo fabric is becoming the Wonder Bread of sustainable textiles. This isn’t to say that bamboo doesn’t have many exceptional qualities. I’m just saying that the green hype is starting to lead to a loss of credibility. Let’s take a short walk through the bamboo green claims and see what’s real and what’s green spin.
Anti-bacterial & UV Protection. “Bamboo fiber has particular and natural functions of anti-bacteria, bacteriostasis and deodorization” due to a “a unique anti-bacteria and bacteriostasis bio-agent named bamboo kun." The mysterious anti-bacterial component has also been called “bamboo chinone”. This unique claim of bamboo fabric is bolstered by studies performed by the Japan Textile Inspection Association; National Textile Inspection Association in China (NTIA), and the Shanghai Microorganism Research Institute. The theory goes that somehow the bamboo kun is chemically bound closely to the bamboo cellulose fibers and this chemical binding survives the harsh chemicals used to free the bamboo cellulose from the lignin and other components found in bamboo when the bamboo cellulose is regenerated into bamboo fiber.
There are two problems to bamboo’s claim for being a uniquely anti-bacterial fabric. The first is that bamboo fabric’s anti-bacterial claim was recently repudiated by research conducted by Colorado State University chemists Subhash Appidi and Ajoy Sarkar, Ph.D., investigating UV-resistant and anti-bacterial fabrics. They reported at the 235th national meeting of the American Chemical Society that “bamboo fabric did not live up to antimicrobial expectations.” Their research also indicated that bamboo fabric is low in UV-resistance and that most damaging ultraviolet rays pass through bamboo fabric to the skin. The research at the Colorado State University directly contradicts many claims and research performed in China and Japan. We need more independent and transparent research to ferret out why the differences.
The second problem is that claims for being an anti-bacterial fabric are not unique to bamboo fabric. Other regenerated cellulose fabrics also claim to have anti-bacterial properties. According to the Lenzing AG web site, “Bacterial growth was observed in various fibers, and TENCEL®, with its rapid absorption of moisture and high absorption capacity proved most effective in inhibiting growth” and “The result demonstrates that TENCEL® is the most naturally hygienic fiber. TENCEL® prevents the growth of bacteria naturally without the addition of chemical additives.”
Unique Bamboo Properties? Thermal-regulating, Anti-static, Biodegradable, Natural UV Protection, Super Soft. Regenerated cellulose fabrics share many common properties. “Green & biodegradable, breathable and cool, soft had feeling, luxurious shiny appearance” are properties commonly found in regenerated cellulose fabrics such as Tencel® / lyocell, Modal®, Viscose® … and bamboo. And this shouldn’t be any surprise as they all derive from cellulose that has been extracted from plants using similar chemical processing and then excreted through spinnerets to form fibers for textiles and clothing.
Research by Y. Xu, Z. Lu and R. Tang at the Testing and Analysis Center at Suzhou University in China used scanning electron microscopes (SEM), Infrared Spectroscopy (IR), and thermoanalyzers (TA) to analyze the physical structure and properties of bamboo viscose, Tencel® and viscose fibers. Their results, which are reported in the Journal of Thermal Analysis and Calorimetry, Vol. 89 (2007), found that all three fibers belong to the cellulose II category and that, while there are variations in the regenerated cellulose fibers that affect fiber properties, the similarities in structural properties are striking. Among their findings was that Tencel® consists of longer molecules and has a greater degree of crystallinity, while bamboo viscose fiber has a lower degree of crystallinity. Differences in fabrics from regenerated cellulose are a combination of factors – some differences in the cellulose cellular structure between the different sources, differences in the mechanical spinning processes when the fibers are formed and the specific chemicals used, and the finishing processes and the enzymes and chemicals used.
Grown on Environmentally Friendly Bamboo Plantations. Bamboo fabric is spun from bamboo pulp manufactured from bamboo grown on bamboo plantations primarily in China. Because bamboo has so many uses and derived products, growing bamboo has become a significant industry in China. The book Rehabilitation of Degraded Forests to Improve Livelihoods of Poor Farmers in South China by Liu Dachang published in 2003 by the Center International Forestry Research researches in depth the environmental and social damage that have been created by poor and over-harvested forests of all kinds, not just bamboo, in China. Chinese government forest policy reforms within the last twenty years have transferred ownership of most forests to private citizens and businesses. The result has been a lack of government regulations for controlling forest land use and many forests were clear-cut to plant money-making mono-cultures such as bamboo plantations.
The adverse environmental impact associated with bamboo plantations replacing natural forests was also documented in a paper by Dr. Jim Bowyer titled “Bamboo Flooring – Environmental Silver Bullet or Faux Savior?”. Because of the severity of the problems, there are now broad initiatives underway in China to rehabilitate degraded forest lands by restoring biodiversity and improving soil and forest conditions. Because bamboo has so many different economics uses such as food products, paper, furniture and housing materials, and textiles, the opportunity and temptation for exploitation of land and resources is great and it is difficult to determine where and under what conditions the bamboo was grown. This is especially a problem for bamboo textiles which are made from regenerated cellulose bamboo pulp because bamboo fiber manufacturers buy their bamboo pulp from suppliers. They don’t manufacture it themselves and there is little transparency in the supply chain.
Here is one example. On their web site, BambroTex proclaims “Bamboo Fibre is a kind of regenerated cellulose fiber, which is produced from raw materials of bamboo pulp by our sole patented technology. Firstly, bamboo pulp is refined from bamboo through a process of hydrolysis-alkalization and multi-phase bleaching. We then process Bamboo pulp into bamboo fiber.” At the same time, Tenbro is declaring “Shanghai Tenbro is the earliest and most specialized bamboo fiber manufacturer in China, and the only patent holder of both material and products of bamboo fiber accredited by State Intellectual Property Bureau.” Both the claims of BambroTex and Tenbro to being the sole patent holders of bamboo fiber are misleading. It seems that Jigao Chemical Fiber Co., Ltd. of China is the actual holder of the patent for manufacturing bamboo fiber in China and the Jigao Chemical Fiber Company produces all the bamboo fiber which Shanghai Tenbro Bamboo Textile Company, China BambroTextile Company, Hebei Jigao Import & Export Company, Jilin Chemical Fiber Import & Export Company, Shanghai Worldbest Company and Minmetals Shanghai Pudong Trading Company export bamboo fiber globally according to the Jigao Chemical Fiber Company.
Things with bamboo fiber are seldom what they seem at first blush. The tens of thousands of tons of bamboo fiber produced by Jigao Chemical Fiber Company for export by its licensed agents such as the Shanghai Tenbro Bamboo Textile Company and the China Bambro Textile Company are manufactured from hundreds of thousands of tons of bamboo plants raised on many thousands of bamboo plantations across China under a wide variety of environmental farming conditions. How can any manufacturer claim that their bamboo fabric is only produced from bamboo grown on environmentally sustainable farms? How do they know where their bamboo was grown and under what conditions? Given the intense emphasis on profits and the lack of transparency in Chinese business and that one company manufacturers the bamboo fibers used in the majority of exported bamboo fabric, claims that only environmentally sustainable bamboo plants are used ring as hollow as a bamboo flute.
The processing of bamboo plants into textile fibers is relatively harmless because caustic soda is the “main chemical used.” Caustic soda, aka sodium hydroxide - NaOH, is one of the ingredients used to reduce bamboo plants to pulpy goo in a process known as hydrolysis alkalization. Caustic soda is a harsh alkaline chemical that must be handled carefully, especially at high levels and under the high temperature and pressure needed for hydrolysis alkalization. As the old saying goes “The poison is in the size of the dose.”
Another toxic chemical in the processing of bamboo rayon is carbon disulfide which has been linked to serious health problems. Breathing low levels of carbon disulfide can cause tiredness, headache and nerve damage. Carbon disulfide has been shown to cause neural disorders in workers at rayon manufacturers.
In Summary. Bamboo fabric has much to offer but much remains to be done before the growing of bamboo can have significant environmentally positive impacts. Here are some steps to produce a more sustainable bamboo fabric:
•The Chinese Government must strengthen their forest reform policies.
•Organic bamboo certifications must be enacted to insure that bamboo plantations are sustainably managed.
•Bamboo rayon fiber manufacturing must be transformed into a closed-loop process to reduce the escape of harsh and toxic chemicals into waste waters, the air and the textile workers environment.
•Commercialize natural bamboo bast fiber processing such as that promised by Litrax so that we can get away from chemically regenerated bamboo viscose rayon.
•And please, make sure that marketing claims match the facts and don’t mislead the consumer.