Room ozonization has been in widespread use to ''freshen'' indoor air
for more than 100 years. This use is sometimes promoted with the claim
that ozone can oxidize airborne gases, and even particulates, to simp
le carbon dioxide and water vapor. Aside from whether ozone can improv
e indoor air quality, the potentially deleterious consequences to publ
ic health of overexposure to ozone are of concern. The literature on b
oth allegations is reviewed. It indicates that ozone is nor a practica
l and effective means of improving indoor air quality, especially in l
ight of its potentially serious risk to health.