An article in the recent, March 15th issue of Chemical & Engineering News took a look at various air-cleaning devices that claim to remove SARS-CoV-2.
Among the technologies discussed were ionizers. When discussing ionizers, ASHRAE (the American Society of Heating, Refrigerating and Air-Conditioning Engineers) warns that some systems may generate ozone. Richard Shaughnessy, director of the Indoor Air Program at the University of Tulsa, also warned “Don’t let anyone tell you that a small amount of ozone is a good amount of ozone. Any increase, even up to 10 ppb, has been shown to have an impact on morbidity.”
The EPA has also linked ionizers to harmful levels of ozone, stating: “Ozone, a lung irritant, is produced indirectly by ion generators and some other electronic air cleaners and directly by ozone generators. While indirect ozone production is of concern, there is even greater concern with the direct, and purposeful introduction of a lung irritant into indoor air. There is no difference, despite some marketers’ claims, between ozone in smog outdoors and ozone produced by these devices. Under certain use conditions ion generators and other ozone generating air cleaners can produce levels of this lung irritant significantly above levels thought harmful to human health. ”