Content area
Full Text
The commercial use of ozone for the removal of indoor air contaminants, including odors, evidently was conceived originally more than 100 years ago.(1) The presumption made to promote ozone for this purpose is that it will oxidize organic compounds to the extent that only carbon dioxide and water vapor remain. This theory is shown in Figure 1. (Figure 1 omitted) In the United States there are several commercial manufacturers of air purifying devices (APDs) that generate ozone. These APDs are sold with the claim that ozone will remove air contaminants from indoor air. Sales of such devices by one leading manufacturer have exceeded 140 000 units.(2) These devices are marketed to homes, schools, businesses, and offices and when used introduce ozone into occupied indoor spaces. Aside from whether the claims of effectiveness are supported, the devices may be capable of producing unhealthy levels of ozone if they are not carefully monitored and controlled.(3)
The focus of this report, in addition to the possible health hazard associated with exposure to ozone, is on the removal of organic contaminants from air by use of ozone. Related issues, which are not reviewed here, include the use of ozone as an effective anti-microbiological agent, use of ozone for odor removal from surfaces (such as after fire damage), and the concurrent use of air ionization. An adequate body of literature exists on these other subjects, and indicates that if provided with high concentrations, while simultaneously providing protection to individuals from exposure to ozone, some control effectiveness may be possible.
To better resolve both the purported effectiveness of ozone for air purification and the health effects of ozone, a literature review was conducted. The primary criterion used for selecting literature was publication in a scientific, preferably peer-reviewed, journal. Also included are the findings and conclusions of widely recognized institutions and public advocacy groups that have studied this subject. There is a large body of anecdotal literature not supported by experimental research and written for promotional purposes. Such literature was not included here.
HEALTH EFFECTS OF OZONE
Ozone is a gas consisting of three oxygen atoms having the molecular formula O sub 3 . The toxicity of ozone to the lung has been studied extensively. Yet most of the research has...