Ozone for use as an antimicrobial for air treatment has been greatly misunderstood. It's unforturnate that the information widely available gives people the impression that ozone creates more problems than it corrects and that most people associate it with smog.
In smog, the irritating effects to humans are caused more by the organic and organic-nitrogen constituents than by the ozone itself. However, since the gas phase analysis of ozone by modern instruments is so accurate and so simple, compared to the analysis of other photochemical smog constituents, and since the concentration of ozone is proportional to the other constituents of photochemical smog, the U.S. EPA has specified that the total photochemical smog be reported as ozone by monitoring stations all over the USA -- a practice which has been adopted in many other areas of the world. Thus, when citizens turn on the TV in the evening and hear that "the air pollution level today is in the danger level for ozone", the negative perception of ozone enlarges.
Ozone is a naturally made gas (the ozone layer and as a component of smog). Ozone also can be man-made, with oxygen as its major starting material. This gas is unstable, however, and quickly reverts back to oxygen in a short time (a few hours in air, a few seconds in aqueous solutions). Ozone must be generated and applied where it is used.
As with chlorine, the trick to safe and successful commercial uses of ozone is to understand its properties, recognize those that are dangerous, and then develop techniques to handle the gas so that it can be applied safely.
In the early 1900s ozone began to be used commercially for drinking water treatment (in France), for odor control in German meat packing houses, and for mold control in German brewery cellars (Horváth et al., 1985; Kuprianoff, 1953). Concentrations of ozone applied for these purposes were rather high (several thousand ppm) for drinking water disinfection) and rather low (0.1 to 10 ppm) for odor and mold control.
The benefits of ozone for these applications were readily apparent, and it was quickly recognized that this new gas was both a powerful disinfectant and simultaneously a powerful oxidizing agent. ~~ Rip G. Rice, Ph.D.
Many hospitals in the U.S. and around the world use large ozone generators to decontaminate operating rooms between surgeries. The rooms are cleaned and then sealed airtight before being filled with ozone which effectively kills or neutralizes all remaining bacteria. The largest use of ozone is in the preparation of pharmaceuticals, synthetic lubricants, and many other commercially useful organic compounds, where it is used to sever carbon-carbon bonds. It can also be used for bleaching substances and for killing microorganisms in
air and water sources. Many municipal drinking water systems kill bacteria with ozone instead of the more common chlorine.
Ozone is industrially used to:
- Deodorize air and objects, such as after a fire.
- Kill bacteria on food or on contact surfaces.
- Kill insects in stored grain.
- Scrub yeast and mold spores from the air in food processing plants.
- Wash fresh fruits and vegetables to kill yeast, mold and bacteria.
Statements of the EPA, Health Canada, and many other health-oriented agencies and associations know the many oxidative and disinfection benefits of ozone can be obtained only when levels that far exceed regulatory standards, are applied. In turn, this means that humans, pets, and ozone-sensitive materials must not be present when sufficiently high levels of ozone are used to solve indoor air problems.
However, in the hands of trained professionals, the results are safe and successful in air restoration procedures.