Is it possible to recycle used paper towels? If so, why aren't there recycling containers for them in public restrooms (like at airports or business offices)? If there is some barrier to recycling them, what would it take to overcome it—be it a process to make them recyclable, or a viable system to collect and recycle them?
Asked by Andy Grubb, '05, Oceanside, Calif.
Paper products
The sticker on the dispenser reads "paper towels = trees," which makes me pause. Most paper towels do indeed come directly from trees, by way of a string of heavy industrial processes that can include bleaching and other chemical processing.
This graphic from The Wisconsin Paper Council describes the industrial papermaking process in five cheery steps, from living trees (1. Forestry) through debarking and chipping (2. Rough processing) and/or addition of recycled paper, to grinding and chemical treatment (3. Pulping) and finally, 4. Paper formation and 5. Paper finishing.
The website outlines each of these steps in more detail, but the machinery in the graphic tells a large part of the story. According to the Green Design Institute at Carnegie-Mellon University, based on the U.S. Department of Commerce's Input-Output tables for industry consumption, each dollar of paper produced results in the equivalent of 892 grams of carbon dioxide emitted.
This calculation takes into account everything from power generation, paper mill operations and truck transportation to the original resource extraction. However, the analysis was done for the entire "sanitary paper product manufacturing" sector, which includes napkins, tablecloths, diapers, tissues and sanitary napkins—any of which may have a greater greenhouse impact than hand towels as they are generally more heavily processed. As a result, the actual greenhouse impact of paper towels may be somewhat lower, but still significant.
Towels can have serious climate and other environmental impacts on the disposal side of the equation as well. Paper towels are traditionally placed in a garbage bin lined with a plastic bag ready to be transported to a landfill. Those plastic bags have their own whole set of climate and other impacts, of course, but they also help ensure that the paper towels decompose in oxygen-limited conditions at the landfill. That results in the production of methane, which has 23 times the greenhouse-warming impact of carbon dioxide, which would be produced if the landfill were aerated.
Blow dryers
The environmental burden from a blow dryer is overwhelmingly the result of the electricity used to run it for an average of 30 seconds per drying cycle. The rated power differs between models, but can be found on the side of the machine (look for a number of watts). The Climate Conservancy did emission calculations for two dryers at 2,300, and 1,700 W in terms of emissions produced and dollars expended. The range from nine to 40 g carbon dioxide depends both on the power of the blow dryer and on the original source of the electricity.
Over a longer term, a second report by the environmental consulting firm Environmental Resource Management (ERM), estimated that stocking a bathroom with paper towels would release slightly less than three times the carbon dioxide equivalent of a bathroom with a blow dryer over five years (1.6 versus 4.6 tonnes carbon dioxide for dryers and towels respectively).
Why so high? In the case of the blow dryer, 98% of the emissions were generated during electricity production, and in the United States most electricity comes from burning greenhouse-gas intensive coal. With more reliance on wind, solar, natural gas or other technologies that cut energy emissions, this burden can be reduced. In the meantime, new dryers such as the Xlerator or the Airblade use high-speed air to cut the drying time and total energy used by more than a third.
Dry hands on the Farm
I still advocate using one's shirt, but it's clear that in most circumstances, using the hand dryer is more environmentally friendly than using paper towels. So why are most of Stanford's public bathrooms equipped with towel dispensers only?
The university has moved towards campus-wide purchasing that supports so-called Environmentally Preferable Products. Despite blow dryers' advantages in environmental, maintenance and financial costs over the product's life, the Stanford Sustainable Procurement Guidelines site boasts, "almost all campus facilities use toilet paper and paper towels made from recycled content." That's much better than virgin paper, to be sure, but even Stanford's newest "green" buildings don't use blow dryers.
The Graduate School of Business' Knight Management Center is still under construction, and is striving for a LEED Platinum rating, the highest level of certification currently offered by the Leadership in Energy and Environmental Design (LEED) Green Building Rating System, from the U.S. Green Building Council. At the Knight Management Center, LEED accredited professional Kathleen Kavanaugh weighs all decisions in terms of five green building rating categories: site decisions, water, energy, materials and indoor air quality. And because blow dryers increase on-site electricity usage whereas paper towels do not, the Knight Center will stick with paper towels.
Over at the Jerry Yang and Akiko Yamazaki Environment and Energy Building (affectionately referred to as Y2E2), it's not just that the bathrooms are stocked with paper towels only. "To be quite honest," says Jeffery Koseff, professor of civil and environmental engineering, who was involved in the intricate design of Y2E2, "I don't recall any discussion about paper versus dryers." Despite thousands of careful design choices along the way, he says, "I think in the end the decision was made by folks who were thinking about how the building was going to be cleaned and serviced."
I did find one hand dryer on the Farm, at the far reaches of the campus, sitting unassumingly in the Carnegie Institute of Washington's Global Ecology Center restroom. The blow dryer is "an educational opportunity for everyone," says Paul Sterbentz, the director of facilities for the Institution. "When people see that blow dryer here, they think it doesn't fit, but it really does. Looking at the total energy from raw materials to finished product you are actually using less when you hit that button," he says. But even at the Global Ecology Building, Sterbentz acknowledges, you "can't move away from paper towels entirely, because you can't get that machine to wipe up spills."
MICKI REAM received her master's in Earth systems in 2010.
