I’ve replaced most of my cleaning supplies with eco-friendly versions, but I’m not sure that Dr. Bronner’s Sal Suds are strong enough to kill all of the nasty bugs in my kitchen. Do green cleaning products work as disinfectants?
Kitchen cleaning pits two modern bogeymen against each other: infectious bacteria and toxic chemicals. Luckily, you don’t need to assuage one worry by ignoring the other—just read labels carefully and exercise some common sense.
There are a number of substances that kill germs, from tea tree oil to the sodium hypochlorite found in household bleach. But not all microbicides are created equal, and their relative effectiveness will depend on a few factors—namely, the kind of organism you’re trying to kill, the nature of the surface you’re trying to disinfect, the duration of the application, and how much of the stuff you put on.
The EPA conducts rigorous efficiency tests on many of the kitchen cleaners that are sold in the United States. Only those that receive a passing grade can be marketed as a “disinfectant” or a “sanitizer.” (For more on the difference between these labeling terms, see this PDF.) If you want to be sure that you’re waging an effective campaign against common food-borne bugs, look for an EPA-registered product that attacks all of them—products are required to list the various microorganisms that they kill—and use it exactly as directed. Use any other kind of cleaner as a germ-killer and you’ll be taking a gamble—since there are no good, published data on how well it might work. (Products designed for human contact, like alcohol-based hand sanitizers and antibacterial soaps, are subject to a different set of regulations, so don’t assume that a product that claims to kill germs on your hands will be effective on your cutting boards.)
At the moment, none of the big green cleaning companies—Seventh Generation, Method, Ecover, or Clorox’s new Green Works line—offers an EPA-registered disinfectant or sanitizer. However, some smaller companies already offer products that meet EPA standards without resorting to ingredients some environmentalists find troubling, such as sodium hypochlorite, phenols, and quaternary amines, or “quats.” PureGreen24, for example, uses an active ingredient composed of silver ions and citric acid, and the company claims the manufacturing process produces no waste or byproducts. The botanical disinfectant Benefect kills germs with thyme oil.
But as with beauty and personal-care products, figuring out exactly how eco-friendly a cleaning product is can be a dicey proposition. Not all environmentalists are convinced that silver is greener, for example—a number of consumer groups are pushing the EPA to stop the sale of products with silver nanoparticles because of their potential toxicity to both humans and aquatic wildlife. Verifying the green cred of a disinfectant or sanitizer is especially difficult because the EPA prohibits these products from being marketed with third-party environmental logos, for fear that such labels make misleading suggestions as to the relative safety or effectiveness of the product. The EPA is currently revisiting the issue. But even if they can’t show the logo on the bottle, some disinfectants have been certified by third-party programs like Canada’s EcoLogo or the United States’ Green Seal—you can check these organizations’ Web sites before you go to the drugstore to find an environmentally preferable product.
What about natural, homemade options? The Internet is full of recipes for DIY “disinfectants” using ingredients like vinegar, baking soda, or borax. These mixtures will probably reduce the number of bugs in your kitchen, but, again, there’s no reason to believe claims that these mixtures are “just as effective as conventional” (i.e., EPA-regulated) disinfectants. According to a 1997 studyon homemade alternative disinfectants, undiluted vinegar and undiluted ammonia did have some antimicrobial effect on E. coli and salmonella, but solutions of ammonia, baking soda, and borax—mixed in concentrations commonly recommended by “natural cleaning” handbooks—were not effective against staph, salmonella, or E. coli. A similar study conducted in 2000 found that vinegar can be as effective as some commercial disinfectants on salmonella and Pseudomonas aeruginosa (a bacterium found in produce) but not very effective at all on staph or E. coli. Baking soda showed “inadequate activity” on all tested pathogens.
The big question, of course, is what level of certainty you require when it comes to cleanliness. Most public health experts stress the importance of basic hygiene practices like proper hand washing, keeping separate cutting boards for raw meat and poultry, and storing and cooking food at the proper temperature—none of which require a special cleaning product. If you do choose to use a disinfectant, though, there’s no need to go overboard and douse every surface in your home. Cutting boards and utensils can be decontaminated with hot water and soap; sponges can be boiled. (See this PDF for fuller guidelines.) Keep the strong stuff for those few items that come into contact with raw meat and can’t fit into your sink—countertops, fridge handles, taps, etc. As always, the greenest course of action here is to cut back and use less.
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