Daniel Smith remembers when he first tried to sell a bamboo floor. The San Francisco entrepreneur thought his woodlike product was attractive and durable, but when he took samples to a Dallas trade show in 1994, the reaction wasn’t quite what he had hoped for. No one believed the plant’s round stalks—then most familiar in the U.S. as the stuff of backyard torches—could be turned into a smooth, lasting floor.
“One architect said to me, ‘I appreciate that you’re at the cutting edge of design and development, but I don’t want to be cut by that edge,” Smith says.
Smith was accustomed to doubts about bamboo. He had spent several years in Taiwan during the early 1980s studying Mandarin Chinese and learning the art of working with laminated bamboo strips. When he returned to the Bay Area, he loaded an orange Volkswagen Squareback with his bamboo art—picture frames and gift boxes—and started visiting local galleries, persisting for an entire year until he made his first sale. Smith later sold elegant bamboo boxes and briefcases to art galleries and museums throughout the country.
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So when Smith decided to expand his business to include bamboo flooring and plywood, he was patient. He made a few small sales and eventually installed a demonstration floor in a San Francisco gallery. Smith and his then business partner James Fong invested in a container of flooring and converted a tea-processing facility in east-central China into a manufacturing plant. Smith & Fong Company’s sales have grown an average of 26 percent a year for the past decade, and the firm now offers products ranging from plywood for kitchen cabinets to flooring for basketball courts.
Because bamboo plants grow swiftly and are purported to require little fertilizer, water and pesticides, many companies now market bamboo as an environmentally friendly material. In addition to flooring and plywood, it is made into fabric—for shirts, socks, towels, even diapers. Enthusiasts can find bicycles, skateboards and laptop computer shells. And the market is no longer boutique: the flooring is available at Home Depot, and bamboo-blend bathrobes can be found at L.L.Bean—both at prices competitive with more familiar materials. In a struggling economy, many bamboo products remain popular.
But bamboo grows halfway around the world, so its journey to North American consumers has a sizable carbon footprint. And product manufacturing is not as “natural” as some of its champions claim. How well do bamboo’s green credentials hold up under scrutiny?
Supergrass
Part of the grass family, some 1,400 species of bamboo grow in a variety of climates and habitats. But most products are made from moso bamboo, which is cultivated in China and elsewhere in Asia. The fastest-growing plant on earth, bamboo can shoot up as much as three feet in a single day, and moso stems can reach 75 feet high and seven inches across—making Chinese bamboo farms feel more like forests than fields.
Unlike tree logs, the hollow, tubular stalks can’t simply be sawed and finished into planks. The most common strategy is to slice the stalks into narrow strips, plane them flat and boil them to remove pest-attracting starches. Manufacturers then dry the strips in kilns, glue them together in flat bundles, subject those to heat and pressure, and finally mill and finish the bundles into conventionally shaped flooring planks or plywood sheets. (Shreds of bamboo can also be soaked in adhesive and pressed into blocks or panels.) Some flooring and plywood retain their original blond color, some are steamed to a darker shade and some are dyed.
Bamboo products vary widely in durability and price. “People believe that bamboo flooring is a meaningful descriptor,” says Douglas Lewis, founder of the Seattle-based company Bamboo Hardwoods. But judging bamboo floors by a single experience, he says, “is like saying, ‘My car doesn’t work, so I’m going to criticize transportation.’ ”
The hardness of bamboo flooring and plywood depends on the maturity of the plant when it was harvested—most experts say the ideal age is five to six years—and the nuances of the manufacturing process. Some floors are softer than a typical hardwood floor, but others are much harder; Smith & Fong’s sturdiest bamboo floor is almost three times harder than oak.
So it’s no surprise that opinions run the gamut. “I’d have an extremely hard time recommending it,” says Kevin Stack, president of Northeast Natural Homes in Syracuse, N.Y., and a green building consultant. When Stack’s company installed a bamboo floor in a medical facility, taking care to pick a type that advertised an appropriate hardness, “everything went great until the occupant moved in,” he says. “The floor got trashed within the first three days.”
Variety notwithstanding, bamboo flooring and plywood (the latter is used for furniture and cabinetry) have gained a reputation for both beauty and environmental virtue. The material now accounts for about 5 percent of the wholesale “wood” flooring market. It appears in suburban homes, federal buildings, posh conference centers, restaurants, even schools, gaining high marks. The William J. Clinton Presidential Center in Little Rock, Ark., recognized for its many “green” features, has bamboo ceiling tiles and about 7,000 square feet of bamboo flooring. “We’ve had over a million people on it—strollers, high heels, wheelchairs, you name it—and it’s held up great,” says Debbie Shock, director of operations and facilities. “I think it’s done extremely well for what it’s been through.”
Growth Industry
Bamboo product manufacturers like to brag about the beauty and durability of their wares, but they are especially proud of their environmental bona fides. “By supporting the use of this beautiful and versatile material as a complete wood replacement, we are all helping to keep the world a greener place!” trumpets the Bamboo Hardwoods Web site.
According to its supporters, bamboo’s fast growth means it sequesters more carbon than slower-growing trees, thus qualifying the flooring and plywood for a “rapidly renewable” materials accreditation under the Leadership in Energy and Environmental Design (LEED) green building rating system [see “MisLEEDing?” by Daniel Brook; Scientific American Earth 3.0, Vol. 18, No. 4; 2008]. Bamboo can be cultivated with little to no fertilizer, pesticides, heavy harvesting machinery or irrigation, and bamboo root systems can protect steep banks from erosion.
Reality, as usual, is more complex. “Any time we can produce a building material out of sunlight, water, air, things like that, we’re way ahead of the game,” emphasizes Alex Wilson, president and executive editor of BuildingGreen in Brattleboro, Vt., whose publications are widely considered the Consumer Reports of the green building world. But, he adds, “we don’t really know a lot about the practices used to grow it. That’s not to say they’re necessarily bad—they may be pretty good in terms of low chemical inputs and so forth—but we haven’t been able to learn much about them.”
Bamboo cultivation has boomed in Asia over the past two decades, and the amount of moso produced in China has more than doubled since 2000. Chinese bamboo generally grows on small, family-owned plots, some of which have been farmed for centuries. “Bamboo is one of the best opportunities farmers have in most of rural China,” says Manuel Ruiz-Pérez, a professor at the Autonomous University of Madrid who has studied bamboo alongside Chinese scientists for the past 15 years.
Opportunity has a dark side, however: in the past, the increased demand tempted growers to clear natural forests and replace them with bamboo—a practice Ruiz-Pérez calls “completely crazy” from an environmental standpoint, because it erodes biodiversity and reduces the carbon capture benefits. But since the Chinese government reformed its forestry policy in the late 1990s, forest clearing for bamboo has been less common, according to Ruiz-Pérez, who has studied bamboo cultivation patterns using satellite imagery. “I’m not saying it doesn’t happen, but we haven’t seen it recently. On the contrary, we see bamboo grown on steep slopes and abandoned agricultural lands”—where, he explains, cultivation is likely a net benefit to the environment.
Farms range from very well managed to poorly managed, so far-reaching green claims are difficult to make. Water and pesticide use seem to be low, Ruiz-Pérez says, but demand can encourage farmers to pump up their use of synthetic fertilizers. Although statistics on fertilizer use in bamboo plantations are scarce, its use in Chinese agriculture in general has exploded in recent decades, leading to a host of environmental problems, including air, soil and groundwater pollution. One bamboo-producing county now offers financial incentives to growers willing to cut back on fertilizer and protect biodiversity, but such efforts are in their early stages.
Made in China
Even bamboo boosters acknowledge that the next steps in the process—those required to transform plants into flooring, fabric or other products—have environmental pitfalls. The glues that bind the strips into planks can contain formaldehyde, posing health risks to workers and possibly to consumers. Dyes can contain heavy metals.
Many consumers also do not realize that almost all the smooth, soft “bamboo” towels, T-shirts, socks and other textiles available in the U.S. are produced through a chemical process akin to the one used to make rayon. (In fact, the U.S. Federal Trade Commission requires most bamboo-based textiles to be labeled as rayon.) The specific details of the fabric production are the subject of much debate, but in general, making rayon includes “cooking” plant materials in lye and treating them with carbon disulfide—chronic exposure to which can cause nervous system damage. The multistep process creates a viscous solution that is extruded through nozzles into an acidic bath, where it hardens into fibers.
Processing is “certainly the major nongreen factor in bamboo fabric,” says Morris Saintsing, a founder and partner of the Andrews, S.C.–based company Bamboosa, which buys bamboo fiber and yarn made in China for its U.S.-manufactured clothing. Bamboosa, like many other U.S. bamboo clothing companies, is a customer of Hebei Jigao Chemical Fiber Company in northeastern China, which advertises its product as a “natural and environment-friendly fiber.” But exactly how much water and energy the company consumes in processing, along with where and how chemicals are used and discarded, is difficult to verify. Such information is “well guarded,” says Dawn Pickering, vice president of Pickering International, a San Francisco importer that is also a Hebei Jigao customer. (Hebei Jigao representatives did not respond to requests for comment.)
Hebei Jigao’s environmental management system is certified by the International Organization for Standardization, meaning only that a system for identifying environmental impacts is in place and that the company is committed to improvements—not that it has attained any particular level of performance.
Clean rayon production is possible: Austrian company Lenzing, which makes a type of rayon fabric from wood pulp, uses a “closed loop” process that recycles essentially all the required chemicals. Pickering, who visited Hebei Jigao in 2008, says the factory does have a sophisticated wastewater treatment system, but a closed-loop process would require an entirely new facility—an enormous investment that she says Chinese companies are not yet willing or able to make.
Although the process that creates fabric is certainly not perfect, bamboo, soy and wood-based rayons are promising alternatives to petroleum-derived fabrics such as polyester, says Rebecca Calahan Klein of Organic Exchange, a nonprofit organization in O’Donnell, Tex., dedicated to greening textiles. “We have a huge chunk of textiles that are nonrenewable. So does a material like bamboo start to move us in the right direction? Yes.”
The Green Standard
It’s not easy for a busy, green-leaning consumer to penetrate this thicket of unknowns and trade-offs. Are bamboo-polyester blend diapers—advertised as “silky soft”—environmentally superior to those made with plain organic cotton? A bamboo skateboard may have eco-chic, but is it more sustainable than one made from maple or fiberglass? Many experts say manufacturers still have some convincing to do. “I think for us to have confidence that bamboo is a sustainable material, the industry needs to step up and support its case that it’s a well-managed green product,” says Nadav Malin, editorial director of BuildingGreen and a member of the Materials and Resources Technical Advisory Group for the LEED rating system.
Despite the difficulties of distance, several companies that sell bamboo products have long-standing relationships with their bamboo growers and tout the responsible practices they have observed on the ground. Companies are beginning to back up those claims with farm and forest certifications. Last year the Organic Crop Improvement Association in Lincoln, Neb., certified that some Chinese bamboo, including that used by Hebei Jigao, meets the U.S. Department of Agriculture’s organic standards. Also last year Smith & Fong obtained a stamp of approval from the Forest Stewardship Council—an organization whose certifiers audit sustainable forestry practices around the world—for 3,000 of the 10,000 acres of bamboo farms that supply its factory.
Certification doesn’t come easy or cheap. Smith negotiated with the council for many years before the organization agreed to consider bamboo. He also paid $35,000 in fees for surveys and other certification process requirements, and he continues to foot the bill for annual inspections and improvements. Because Chinese bamboo is generally farmed in small parcels, certification means manufacturers or importers must hire extra staff to coordinate the activities of hundreds of farmers.
The certification of farms is just one stop on the road to environmental credibility, of course, and consumers must often choose among imperfect alternatives. Alex Wilson of BuildingGreen cautions that in regions where hardwood trees are plentiful, such as the northeastern U.S., wood from well-managed local woodlots, certified or not, would likely be a greener flooring choice than certified bamboo, in part because of the carbon costs of shipping and trucking products from China. Wilson has proposed that the LEED “rapidly renewable” credit that bamboo receives be replaced by a broader credit that includes trees and other “bio-based” materials, given that timber—which in some cases requires no fertilizer or herbicides—may be environmentally preferable to fertilizer- or pesticide-intensive agricultural crops.
Meanwhile questions persist about the environmental and human health effects of bamboo product manufacturing. Companies such as Smith & Fong, which owns a stake in its Chinese manufacturing plant, can exercise more control over processing; Smith & Fong and various other manufacturers and importers, including Teragren on Bainbridge Island in Washington State, now offer bamboo flooring and plywood made with formaldehyde-free glue. Hebei Jigao and other bamboo fiber companies have acquired the international Oeko-Tex certification, which attests that final products are free of harmful chemicals—although it does not fully address how factory chemicals are used and disposed of or how much water and energy are required during manufacturing.
Smith, whose company is experimenting with ways to replace its formaldehyde-free glue with a nontoxic, soy-based one, says he welcomes the continued pressure to improve. “People will say, ‘Well, okay, smart guy, you took care of that issue, but what about this one?’ People are becoming both more educated and more concerned about the environment, and they’re asking more hard-hitting questions. But these increasing demands show us the road ahead.”
Note: This article was originally printed with the title, "Bamboo Boom."