We’ve never been particularly impressed with the proliferation of air purifiers — maybe we just missed the days when Sharper Image sold cooler stuff, or maybe it’s because there’s so little evidence on their efficacy. Well, there’s some new evidence today, and it’s quite… ironic:
Nizkorodov and colleagues tested various air purifiers in homes, offices and cars. In many cases, ozone levels inside climbed above 90 parts per billion, exceeding California’s basic safety threshold. In some cases, ozone soared higher than 350 parts per billion, which if measured outside would trigger a Stage 2 Smog Alert, an event that hasn’t occurred in the Southern California coastal air basin since 1988.
California lawmakers are considering legislation to reduce emissions from indoor air purifiers. Meanwhile, both the state and the U.S. Environmental Protection Agency have issued advisories discouraging their use.
“These machines are insidious,” said Barbara Riordan, acting chairperson of the California Air Resources Board (ARB), in a warning last year. “Marketed as a strong defense against indoor air pollution, they emit ozone, the same chemical that the ARB and … U.S. Environmental Protection Agency have been trying to eliminate from our air for decades. More chilling is that some people susceptible to the ill effects of ozone will eagerly bring these Trojan horses home.”
Science does not even suggest the things do what they’re purported to do.
An EPA fact sheet has this to say about air purifiers: “Available scientific evidence shows that at concentrations that do not exceed public health standards, ozone has little potential to remove indoor air contaminants. Some manufacturers or vendors suggest that ozone will render almost every chemical contaminant harmless by producing a chemical reaction whose only by-products are carbon dioxide, oxygen and water. This is misleading.”
We look forward to Sharper Image and Brookstone rebranding these sham devices — may we suggest, “give your home that urban feel, with an ozone dispenser.”
More from MSNBC (via engadget)
Abstract & Implications from the Journal of the Air & Waste Management Association…
As well as some efforts to measure purifiers’ effectiveness…
Update: For proper balance, please read our readers’ commentary.