Growing numbers of people with allergies and asthma are coughing up hefty sums for heavily marketed indoor air cleaners they hope will provide purer air to breathe.
But a study in the May issue of Consumer Reports describes some of these devices as not just ineffective but capable of exposing people to ozone -- a gas that, in large enough quantities, can damage the lungs, irritate the respiratory system and aggravate asthma, according to the Environmental Protection Agency (EPA).
Sharper Image's Ionic Breeze ionizing air cleaner, at right, failed a Consumers Union test by producing what CU called dangerous amounts of ozone. A Whirlpool HEPA air cleaner, above, did better. Sharper Image disputes the findings and insists its product is safe.
Sharper Image, whose Ionic Breeze cleaner ($400) drew particular criticism in the report, disputed the findings, saying its product is "safe" and produces only "trace levels of ozone as a byproduct," according to a printed statement to which the company referred news media. Other manufacturers whose products did poorly in the report also found fault with the study methods and the findings.
The devices, known as ionizing air cleaners or electrostatic precipitators, work by electrically charging airborne particles and trapping them on oppositely charged metal plates, according to the American Lung Association (ALA). Ozone, a super-charged oxygen molecule, is a byproduct of this process. In contrast, says the association, the most common type of air purifier includes a high-efficiency particulate air (HEPA) filter, which traps most particles and removes odors while producing much lower amounts of ozone.
The findings are particularly worrisome because about 80 percent of people who buy air cleaners have asthma or allergies, according to the magazine. Air ionizers make up about 25 percent of the $410 million-a-year air cleaner market, according to the report, which was issued by the nonprofit Consumers Union (CU), publisher of Consumer Reports books and magazines. The report marks CU's second criticism in two years of the Ionic Breeze ($400), which leads the ionizer market. Once again, the product earned "poor" ratings from CU for cleaning dust and smoke from the air; the new report also found the device poor at removing pollen.
Sharper Image sued CU for libel after an October 2003 report said that the Ionic Breeze performed poorly at removing dust and smoke particles from the air; a federal court dismissed the suit.
The more than 1 million Ionic Breeze units sold testify to the machine's effectiveness, said E. Robert (Bob) Wallach, legal counsel for Sharper Image.
Ionizers, advertised in TV commercials, infomercials and magazines, are typically sleek and slender and have quieter motors than other types of portable air cleaners. And there are many potential buyers: 18.2 million adults had hay fever in 2002, according to the National Center for Health Statistics, and about 21.9 million had asthma.
Jeff Asher, vice president and technical director at CU, said air ionizers give off a deceptively "fresh air" smell, similar to the scent just after a thunderstorm. Buyers, he said, "think that this is a good smell . . . that in fact, without that smell, that the ionizer isn't cleaning the air." But what they smell, Asher said, is actually ozone.
Richard Thalheimer, founder, chairman and CEO of Sharper Image, issued a sharply worded statement disputing the findings. "This Consumer Reports piece is, in my view, irresponsible in the way it casually and unscientifically speculates about public health and safety," the statement read. Calling the report "an unfair assault by Consumers Union," it stated that the Ionic Breeze was no different than many common household electronic devices, such as TVs and hair dryers, in producing "trace levels of ozone as a byproduct."