“Odor-free! State-of-the-art dry cleaning,” proclaims the sign in the window of Lou’s Cleaners in Garden City, Long Island. The shop’s owner, Morton Fenster, just invested $30,000 in a new self-contained cleaning machine designed to eliminate emissions of perchloroethylene, known as “perc,” the solvent he uses to clean his customers’ clothes. “I did it mostly for me,” Fenster says. “I couldn’t stand the smell of cleaning fluids.” But the sign has also reassured customers made apprehensive by recent media reports about the dangers of perc.

A highly effective solvent, perc was first used in the 1930s and today is used by about 90 percent of the nation’s dry cleaners. (Most others use petroleum-based solvents.) Garments are immersed in perc, which dissolves dirt and grease, then dried and pressed. When clothes are moved from the equivalent of the washer to the dryer, some perc can escape into the air-a problem solved by using a self-contained machine that, like Fenster’s, combines the washing and drying processes.

In 1992, the environmental group Greenpeace began a campaign against perc, making dramatic claims about its dangers. “Dry cleaning your clothes can damage your health [and] the health of your family as well as the health of workers in dry-cleaning shops,” wrote Susan Leubusher, a Greenpeace staffer, in an article published by the organization. Local media, including the Village Voice and WCBS-TV, joined in, highlighting the supposed risks of dry cleaning. “Don’t store your newly dry-cleaned clothes in a child’s room,” warned the September 1992 issue of Consumer Reports. “Since children are smaller than adults, they’re more sensitive to toxics [sic].”

But the environmentalists wildly overstate the case. The federal Environmental Protection Agency classifies perc as a “possible human carcinogen,” a category that also includes saccharine, peanut butter, and mushrooms. The EPA’s Science Advisory Board considered changing the solvent’s classification from “possible” to “probable” cancer risk at least four times in the past 13 years, and each time decided against it on the grounds of insufficient evidence.

Nonetheless, government regulators responded to the flurry of media attention. The EPA began a study of dry cleaning and is drafting new regulations. In Albany, the state Department of Environmental Conservation has proposed regulations requiring that all dry cleaners upgrade their equipment to contain perc emissions. The new cleaning machines cost up to $60,000 each, depending on their capacity, an expense that could put some dry-cleaning shops out of business. A typical dry-cleaning establishment has five employees and net profits of $10,000 per year, according to a 1988 EPA report.

In an article published in the Fall 1991 issue of Industry and the Environment, a journal published by the United Nations Environmental Program, Greenpeace International’s Beverly Thorpe laid out the most comprehensive case against perc. She cited scientific studies of workplace exposure that have linked perc with cancer and other ailments, laboratory studies of rats and mice, and computer model extrapolations. Thorpe’s conclusion was the subtitle of her article: “Time for a Global Ban.”

The evidence, however, is not so clear. The human studies Thorpe cited all had methodological problems. Five U.S. studies found a correlation between perc exposure and health problems among dry-cleaning workers. “None of these studies has been accepted as absolute proof,” Thorpe conceded, “either because the number [of people] surveyed was too small or because not enough was known about the subjects to be sure they were exposed solely to perc.” Other studies, conducted overseas, failed to account for the effects of risk factors such as smoking and heavy drinking.

Thorpe’s other sources of evidence were even more questionable. In tests on rats and mice, the rodents are forced to consume doses thousands of times greater than any person could possibly be exposed to in a lifetime. And computer models are notoriously unreliable, reflecting the biases of their programmers. It is typical for scientists on opposing sides of risk-analysis debates to employ dueling computer models that show opposite results.

The best study on the effects of perc, moreover, contradicts Thorpe’s conclusion. The National Institute for Occupational Safety and Health, a federal agency, found no increase in cancer among six hundred dry-cleaning workers. The study is particularly reliable because it is the only one ever conducted whose subjects were exposed to perc and no other cleaning solvents.

Because the evidence against perc is so weak, we are a long way from Thorpe’s global ban. Even the World Health Organization, normally a proponent of strong environmental regulation, says perc should not be banned without “international consultations regarding an alternative.”

Few alternatives exist, however. While perc is nonflammable, fire codes limit the use of petroleum-based solvents. Two other solvents used in the past are now banned as ozone-depleting chemicals. At the EPA’s request, the Neighborhood Cleaners Association, an industry group, is testing a process dubbed “Ecoclean” that involves extensive spot cleaning with organic cleansers, vacuuming of dirt, tumble drying, and steaming. Because it is labor-intensive and does not clean as thoroughly as perc, however, Ecoclean does not look promising.

Greenpeace, for its part, would like to end dry cleaning altogether. “With increased awareness, consumers would not choose fabrics that stipulate ’dry clean only,”’ Thorpe writes. “At the same time, the fashion industry must become accountable for the choice of textiles used.” Even Greenpeace’s Leubusher, however, admits that perc is no more hazardous than such household chemicals as paint strippers or pesticides used on indoor plants. And the EPA has rejected the environmentalist claim that a hazard is posed by trace amounts of perc left on clothes after cleaning.

Perc can be an irritant for people who live in apartments directly over dry-cleaning plants, a fairly common arrangement in New York City. In light of the federal study showing no danger to dry-cleaning workers, it is unlikely that the health of these apartment dwellers is in jeopardy. But perc smells bad, and in the wake of local media coverage in January, the Health Department received at least seventy complaints from city residents who live over dry-cleaning plants. In 14 of those cases, levels of perc were found to exceed the state’s safety standard. That standard, however, is ridiculously low-so low, in fact, that it is well under the minimum amount of perc that can be measured using existing equipment. And perc emissions can be kept out of apartments altogether if dry-cleaning establishments improve ventilation, install plastic seals, or upgrade to self-contained cleaning machines.

City, state, and federal regulators should take a long, careful look at the evidence before slapping dry cleaners with burdensome new regulations. If new restrictions are found to be necessary, they should be accompanied by tax credits to help dry cleaners defray the cost of compliance. The struggling immigrant families who operate most of the city’s 1,800 dry-cleaning establishments should not be sacrificed in the name of an overzealous environmental crusade.


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