Confronting Chlorine

To achieve its pearly white color, most paper goes through a bleaching process that uses some of the world’s more toxic chemicals. Assuming we can’t live without bright white paper, does it have to be bleached with chlorine, or are there feasible alternatives?

Paper is traditionally bleached with chlorine and chemicals derived from it (such as chlorine dioxide). The process also removes lignin, a component of wood fiber that can eventually turn paper yellow. Archie Beaton, executive director of the Chlorine-Free Products Association, says that chlorine produces toxins known as organochlorides, including dioxin, that eventually wind up in waterways.

In addition, Beaton says bleaching paper with chlorine uses vast amounts of water. "It takes 10.15 gallons of water to produce a six-and-a-half-ounce booklet," says Beaton. "[Using a chlorine-free alternative] uses less than a half gallon per booklet."

Chlorine also has side effects that are seen across the globe, sometimes in places nowhere near the paper mills that produced them. According to Greenpeace, these pollutants have been found in the Arctic, where polar bears, whales and marine mammals have elevated chlorine levels.

Numerous health problems are linked to the exposure of these chemicals.Reduction in sperm counts, alterations in sexual behavior, birth defects, disruption of female reproductive cycles and spontaneous abortions have been linked to chlorine.

For the eco-friendly consumer looking to help keep these polluting effluents at bay, alternatives do exist. According to the California Integrated Waste Management Board (CIWMB), "totally chlorine free," or TCF, paper uses alternative methods, including hydrogen peroxide and oxygen. Other paper products, including brown paper bags and cardboard boxes, are unbleached and therefore chlorine-free. TCF paper can have no recycled content, and so is made from 100 percent virgin fibers, which can include both wood as well as other fibers such as kenaf and hemp.

Even more friendly to the environment, according to CIWMB, is "processed-chlorine free," or PCF, paper that not only rids the bleaching process of both chlorine and chlorine derivatives, but can also have up to 100 percent recycled content. For paper to be labeled PCF, it needs a minimum of 30 percent post-consumer content, and the rebleaching process cannot include "chlorine-containing compounds." It’s not chlorine-free, because chlorine is imported in the post-consumer material.

The third type of chlorine-free paper, "elementally chlorine-free," or ECF, is the most controversial. It uses chlorine derivatives, such as chlorine dioxide, that CIWMB says can "still produce toxic chlorinated organic compounds, including chloroform, a known carcinogen."

The American Forest and Paper Association (AF&PA) claims that many members have switched to ECF in many pulp mills across the country, and it now accounts for 96 percent of bleached chemical pulp production in the U.S. More than $1 billion has been spent over the past 15 years to clean up the industry, says AF&PA, which maintains that ECF provides similar benefits to TCF and PCF. "Dioxin cannot be detected in wastewater being discharged from [ECF] pulp and paper mills," says the trade group.

Of course, paper can be whitened without chlorine. Catherine Almquist, assistant professor at Miami University in Oxford, Ohio, says the process of oxygen bleaching (also known as oxygen delignification) can be used during the first stages of lignin removal instead of chlorine. "Since oxygen is used to bleach the lignin, you don’t have the chlorine problem, so the effluents can go back into the recovery system, and the chemicals can be reused," says Almquist.

Hydrogen peroxide is another frequently used alternative. It is used as a brightening agent for high-yield pulp and is typically used in the latter steps of the bleaching process. The effluent can also go back into the recovery system instead of being emitted into a waterway, and it can be used again. Enzyme bleaching is another substitute, in which enzymes are used to remove lignin without damaging the carbohydrate fibers in the pulp, but Almquist says this is not used commercially yet. Even ozone can be used, in a process that involves passing an oxygen stream through a UV light, eventually generating ozone that passes through the pulp to whiten it.

While Almquist says oxygen-enhanced bleaching techniques are becoming very popular, most paper mills are sticking with ECF technology, which is the minimum standard for mills to operate. These alternatives may one day result in the complete phasing out of chlorine derivatives. Meanwhile, Beaton says that alternatively bleached papers are available in test markets at Staples stores across the country.

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