How toxic is dry cleaning?

Illuminating answers to environmental questions.
March 9 2010 7:23 AM

Dirty Laundry

Should I give up dry cleaning?

Illustration by Mark Alan Stamaty. Click image to expand.

I live around the corner from a dry cleaner, but there's also a "green" dry cleaner on the other side of town. Am I total jerk if I keep going to my regular spot?

The problem with traditional dry cleaning is a liquid solvent called "perc," short for perchloroethylene. (Despite the moniker, dry cleaning isn't really dry; it just doesn't involve water.) Perc is what dissolves the gunk off of your clothes. It's highly effective without being labor-intensive and—unlike the cleaning chemicals of old—it's not likely to burst into flames. That's why cleaners have been using it for the past 50 years.

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People have been concerned about the chemical's health risks since the 1970s. Perchloroethylene (also known as tetrachloroethylene) is considered a toxic air pollutant by the EPA, meaning that it's "known or suspected to cause cancer or other serious health effects." Short, intense blasts of perc can cause dizziness, headaches, or loss of consciousness. But how dangerous is long-term exposure? Indoor and outdoor air usually contains a few micrograms of perc per cubic meter. At those background levels, the New York State Department of Health estimates that there's a theoretical risk of up to five additional people in 1 million developing cancer after a lifetime of exposure. (Some agencies have calculated slightly higher risks; California's Air Resources Board, for example, estimates an additional six to 30 cases of cancer at those background levels.)

In and around dry cleaners, the air is likely to be more contaminated. According to one study done in New York City between 2001 and 2003, the air in apartments above dry cleaners had average perc levels of 34 micrograms per cubic meter. If exposed to those levels over a lifetime, the New York Department of Health estimates that an additional 34 people in 1 million would be at risk for developing cancer. New York recommends that residential air contain no more than 100 micrograms per cubic meter. You can start smelling perc—which has a "sharp, sweet odor"at around 30,000 micrograms per cubic meter.

Not all dry cleaners are created alike. For example, in that New York study, some apartments above dry cleaners showed perc levels that weren't much above background, while others were contaminated with as much as 5,000 micrograms per cubic meter. (The most polluted air was found in low-income and minority neighborhoods.) The authors of the study noted that all of the cleaners involved were using up-to-date equipment, so thedifference between the high- and low-emitters was likely a result of poor work practices (PDF) or lousy ventilation in the building.

The problem is, there's no easy way for you, as a consumer, to figure out how clean your local cleaner happens to be. If you want to limit your personal contribution to the perc problem, your best option is to check whether any of the clothes you normally get dry-cleaned can be laundered and pressed instead. Remember, too, that cleaning chemicals are only part of the green equation: It's also worth asking your dry cleaner if he'll let you use a reusable garment bag instead of those plastic, disposable ones.

Meanwhile, if you do decide to drive cross-town, remember the cardinal rule of responsible consumption: Just because a company says its product is green, that doesn't magically make it so. There are a number of new garment-care processes on the market, and just about every one that uses a nonperc solvent is billing itself as eco-friendly.

One method that seems to have gained relatively wide acceptance from both environmentalists and professional garment care cleaners is wet cleaning, which is like a souped-up version of what you do at the laundromat. Garments are cleaned in computer-controlled washers and dryers using soap and water, and then reshaped using specialized equipment. Wet-cleaning has the added benefit of being the most energy-efficient of all the alternatives (PDF), since the used wash water can go straight down the sewer. (In all other systems, solvents must be recovered, which requires lots of additional energy.) It does, however, require more water than any other process, and it's more labor-intensive than traditional perc cleaning, which may drive up the costs. The consensus seems to be that, with skilled technicians and the most up-to-date machinery, wet cleaning can be as safe and effective as dry cleaning.

If the "green" cleaner in your area is using a different method, the Lantern suggests doing some homework before you start sending them your suits and blouses. This fact sheet (PDF) from California's Air Resources Board is a good place to start. Be especially wary about any dry cleaner that bills itself as "organic." Sneaky greenwashers often use the term in its strict chemistry-class sense—i.e., that the solvent being used is carbon-based. Under that definition, even perc is organic.

Is there an environmental quandary that's been keeping you up at night? Send it to ask.the.lantern@gmail.com, and check this space every Tuesday.

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