A review of the safety of ozone (10028156) generating devices and their ability to improve air quality was presented. Reports on the health effects of ozone at various concentrations were cited as well as current exposure standards. These standards included the National Ambient Air Quality Standard (NAAQS) of 120 parts per billion (ppb) averaged over 1 hour (hr), the OSHA permissible exposure level (PEL) of 100ppb averaged over an 8hr day, and the Food and Drug Administration limit of 50ppb for ozone generating devices in enclosed, occupied spaces. The limits of olfactory detection of ozone and rapid olfactory fatigue were discussed. Reported halflives of common residential air contaminants in the presence of ozone were listed. In a discussion of ozone chemistry, it was pointed out that only unsaturated alkenes showed significant reactivity with ozone. The products of such reactions were aldehydes, ketones, and organic acids, which may be more toxic than the precursor alkene. Experimental evidence demonstrated the occurrence of such reactions when ozone generating devices were used in the presence of alkenes. Other cited reports suggested a potential for excessive exposure and questioned their effectiveness in removing air pollutants. The author concludes that while the levels of ozone produced are higher than permissible levels, they are still too low to remove contaminants from air. Dilution ventilation is suggested as a safer and more efficient way to improve indoor air quality.