Ozone is a colorless gas composed of three oxygen atoms (O3). Though colorless, it is responsible for the faint blue afterglow of electric discharge. The oxygen that we need in the air we breathe has molecules of two oxygen atoms (O2). Airborne O3, created by ultraviolet radiation in the upper atmosphere and by lightning, is almost always present. It is also created by electric arcs, automobile exhaust, and some industrial processes.

O3 is a toxic gas with vastly different chemical and toxicological properties from O2. It is chemically reactive, and destroys itself by attacking other chemicals. The problem is it's relatively long survival time (half-life) in air: up to three days! Water purification by ozonation is safe, because O3 decays as quickly as 30 minutes there. O3 air purifiers are not safe for routine, daily household use.

The word is derived from the Greek word for "smell" because its odor can be detected at concentrations as low as .0076 parts-per-million (ppm).

O3 is the main component of smog. California’s EPA recommended lowering the state's outdoor limit to .070 ppm. World Health Organization standards are .060 ppm. The Food and Drug Administration (FDA) requires O3 output of indoor medical devices to be less than .050 ppm. Underwriters Laboratory's UL Standard 867 requires household electrostatic air purifier ozone to be no more than .050 ppm. The Consumer Product Safety Commission is evaluating whether the .050 ppm voluntary industry standard is adequate protection for consumers.

There is a consensus among environmental, health and safety agencies that workplace exposure of up to 0.10 ppm is acceptable for an eight-hour period. The United Kingdom Health & Safety Executive has established an occupational O3 exposure limit of 0.20 ppm for 15 minute periods. These are industrial exposure standards: want a job as a coal miner, Alaska crab boat crew, or offshore oil-rig diver?

Well, there are frequent openings.

There’s No Place Like Home

In the absence of O3 generators, indoor levels are much lower than found outdoors. Indoor devices that produce O3 include hair dryers, TVs, laser printers, copy machines, computers, fax machines, and many electronic air purifiers. Substantial amounts come indoors from outdoors.

Ozones Effects on Health:

The health effects of O3 have been studied extensively.

The bleach hydrogen peroxide is formed when O-3 dissolves in water, like when it comes into contact with moisture in your eyes, nose and lungs. Those who understand the danger of the “fresh” bleach-like smell of O3 can avoid it, but many people believe the ads and like the “improved” odor.

Concentrations above .080 ppm for eight hours or longer cause coughing, wheezing, and chest pain. At this level asthma symptoms worsen, the sense of smell decreases, and permanent lung damage is possible. High concentrations increase sensitivity to pollen, mold, and other allergy triggers.

Recent studies of cumulative effects also raise concerns. A 14-year study of 95 urban areas in the U.S. found a clear link between small increases in O3 and higher mortality rates.

Tri-atomic oxygen reacts with lemon and pine-scented cleaning products and air fresheners, creating toxic formaldehyde. If you still have scents and “air fresheners” anywhere in your home, I urge a hasty visit to the nearest dumpster! My readers already know that these products are symptom maskers which only make long term solutions harder.

Ozonating Air Purifier: The Great and Powerful Oz

There are no legally binding air purifier emision limits; EPA regulates only outdoor air, FDA regulates only medical devices. There is no federal mandate for ozone-free indoor air.

The best application is in deodorizing hotel rooms. The O-generator is turned on full power, windows and doors are closed and the room is left empty. When the room is odor free, staff returns, turning off the machine. Maybe they ventilate the air. Do they wait until the room is completely aired out before you check in?

Manufacturers of ozone machines claim the air is cleaned and the gases, chemicals, and microorganisms are destroyed in the air. This air purification is by oxidation, reactions with pollutants which break them down, sometimes into additional pollutants. This is a powerful purifying technology, but ozone in air must reach toxic levels 50 times the outdoor air purity standards to be effective against microorganisms.

Ironically, it is the high-quaity, high powered generator that poses the greatest danger to consumers. High power O-3 “Shock Treatments” are toxic to people, pets, and even houseplants. Honest vendors will properly advise customers on how to use this powerful air purification tool safely, but many do not, luring consumers into buying a purifier which is dangerous when used continuously on high settings.

Some very popular "air purifiers" are mid powered ozonators and little else. The Ecoquest product line falls in this category.

O3 covers indoor odors by numbing the sense of smell, as much as by purifying the air. Particulates are not removed from the air, since there are no filters.

The air purifier is frequently marketed with misleading terminology; "energized oxygen", "trivalent" oxygen, "activated" oxygen, "allotropic" oxygen, "saturated" oxygen, "super oxygen," or "mountain-fresh air." Since ozone accompanies thunderstorms, nature imagery is often invoked.

The purifier is sometimes sold with an add-on ionizer, further obscuring its true character. Please do not use an air purifier with ozone emissions indoors when people or pets are at home. O3 is useful in unoccupied homes and industrial applications only. The Canadian government has banned the sale of ozone generators.

O3 air purification is very useful for whole-house high-dose mold remediation by professionals or well-informed consumers. In the case of mold, source removal may be impossible, and less powerful methods may fail.

Air purifier emissions should not be added to the long list of routine dangerous household exposures. Again for emphasis: an ozonator air purifier is a powerful tool, but not for everyday use.

Many poeple report improved allergy/asthma symptoms when using these air purifiers. Yes, ozone may be useful as an alternative medical therapy. I have done some oxygenation experiments myself. But I will not use, or recommend for normal use, an air purifier that produces ozone other than trace amounts below .01 parts per million.

Ozone air purifiers often emit oxides of nitrogen and other impurities which render them unsuited as therapeutic tools.

“I'll get you, my pretty - and your little dog, too!”