An investigation by Consumers Union (CU) -- the products testing group that publishes Consumer Reports -- found that five of the best-selling models tested emitted relatively high levels of ozone.
Ozone exposure can aggravate allergies Ozone exposure can aggravate allergies and decrease lung function. It is a harmful gas resulting from car exhaust, gasoline vapors, and other pollutants.
"It is both misleading and irresponsible for an organization like Consumer Reports to suggest that there is any potential harmful effect from a product that tens of thousands of people have purchased and are using every day without adverse consequences," Sharper Image spokesman and general counsel E. Bob Wallach tells WebMD.
A recent study showed that short-term increases in ozone levels in the outside air contribute to thousands of deaths a year in the United States.
In an October 2003 report, CU researchers concluded that ionizing purifiers do a much poorer job of cleaning the air of dust and smoke than their advertising suggests. The report led to a lawsuit against the consumer group by Sharper Image Corp., which makes the top-selling ionizing air purifiers -- the Ionic Breeze line.
The suit was dismissed in November of last year, and Sharper Image has since agreed to pay just over half a million dollars in court costs.
While acknowledging that the new ozone tests did not show that the air cleaners pose a clear health hazard, Consumers Union vice president and spokesman Jeff Asher says they did suggest a potential risk. None of the ionizing air purifiers tested exceeded a generally accepted ozone safety level when the air was measured 3 feet away.
"The bottom line is that these products don't work anyway, so why would anyone want to expose themselves to a level of ozone which, when added to the ozone that is already in the home, certainly isn't going to do them any good?" Asher tells WebMD.
Wallach added that the Ionic Breeze model used in the latest test has been shown to comply with federal regulations for safe ozone emissions.
CU's latest investigation included Sharper Image's Professional Series Ionic Breeze Quadra S1737 SNX, and four other top-selling brands of ionizing air cleaners: Brookstone's Pure-Ion V2; Ionic Pro CL-369; IonizAir P4620; and Surround Air XJ-2000.
The findings are published in the May issue of Consumer Reports.
All five of the ionizers failed CR recommendations, with overall failed scores based on the air cleaner's ability to remove fine dust, smoke, and pollen from a test chamber. They also failed the standard sealed-room testing for ozone levels by producing more than 50 parts per billion (ppb) of ozone detected within 2 inches away from the machine over a 24-hour period.
They all fared better, however, when the tests more closely mimicked conditions in a typical home. In tests measuring ozone levels 3 feet away from the machine in a well-ventilated room, the Brookstone cleaner Pure-Ion V2 emitted the least ozone at 2 ppb and the IonizAir P4620 model emitted the most, at 28 ppb, according to Asher.
"Fifty ppb is the accepted cutoff level for safety, and clearly the worst (ozone emitter) tested generated just over half of that," he says. "So, one might conclude that there is no danger with these machines. While for most people that is probably true, some people do seem to be particularly susceptible to ozone."