Response: It is true that traditional dry cleaning methods are not "environmentally friendly". This is because most dry cleaners use the chemical perchloroethylene (also called perc, tetrachloroethylene, C2Cl4 and Cl2C=CCl2) to clean your clothes. Research studies have shown that perchloroethylene exposures may be dangerous to your health, having been linked to increased risks of bladder, esophageal, and cervical cancer, eye, nose, throat and skin irritation, and reduced fertility, among other effects. These findings have been shown for people working at dry cleaners, who are routinely exposed to high amounts of perchloroethylene, either through inhalation or through skin contact. People who work in dry cleaners are not the only ones exposed to perchloroethylene. Low levels of perchloroethylene can also be present in your indoor air, as any perchloroethylene that was not removed in the dry cleaning process will be on your clothes that you bring home. Once at home, the perchloroethylene will leave your clothes and go into the air. Also, since dry cleaners are fairly common in communities, relatively low levels of perchloroethylene can also be found outdoors from "fugitive emissions" or leaks that are not controlled. Perchloroethylene can also be found in your private and public drinking wells. Importantly, these air and water levels are substantially lower than federal standards; however, it is not known whether these low level exposures are dangerous to health.
The actual and potential dangers of perchloroethylene exposures have focused considerable attention on ways to reduce their risks. Risk reduction methods have followed two distinct but compatible strategies. The first strategy is to reduce perchloroethylene emissions from dry cleaners through improvements to equipment, maintenance, work procedures, and ventilation. While effective and important in the short run, this emission reduction strategy does not provide a permanent fix, as it still relies on the use of perchloroethylene, a known health threat. For this reason, the second strategy -- to phase in alternative, non-polluting cleaning methods -- makes an attractive permanent solution to the dry cleaning problem.
There are three commonly discussed alternatives to dry cleaning by perchloroethylene, including liquid carbon dioxide (CO2) (Hangers Cleaners), silicone-solvent based (GreenEarth Cleaning), and wet (or soap and water) cleaning methods. Although not completely characterized, each of these alternative methods would be a cleaner (pardon the pun) substitute for perchloroethylene. The CO2 and wet cleaning methods are thought to be the most environmentally and public health friendly. While the silicone-method is also thought to be environmentally friendly, there are mixed reports about its health risks.
An equally important question, though, is how they clean. Consumer Reports compared the cleaning ability of these methods with each other and with the traditional perchloroethylene method. Their results showed that the CO2 cleaning method performed best, with silicone-solvent based cleaning a close second. The performances of both wet-cleaning and perchloroethylene cleaning were weak in comparison, especially for a lambswool jacket -- which does not bode well for your cashmere sweaters.
Despite the strong performance of the CO2 and silicone methods, they are not available everywhere just now. Their use is currently limited by the costs of installing or switching to these methods, which are highest for the CO2 followed by the silicone-solvent based methods. These high costs are particularly burdensome for the typical small business dry cleaner. If you are lucky, however, you will have a conveniently located "green" cleaner near you. To check, the location of cleaners using the CO2 method, however, can be found at the Hangers Cleaners website (www.hangersdrycleaners.com), while cleaners offering silicone-solvent cleaning are on the web site www.greenearthcleaning.com.
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Helen Suh MacIntosh is a professor in environmental health at Harvard University and studies how pollution behaves in the environment and how it affects people's health. Please keep in mind that her answers are just her interpretation of available information and should not be taken as the only viewpoint or solution to a problem. Use this column at your own risk. Having said this, please feel free to post any of your environmental health questions to AskTreeHugger [[@]] TreeHugger [[.]] com. (Please use a descriptive email subject line and mention if you want to remain anonymous).