Ozone Home Cleaning

An online search of the title of this article resulted in three articles published by the Environmental Protection Agency in an effort to disabuse the public of the belief that ozone generating machines improve indoor air quality. These machines claim to purify the air with "energized" oxygen, removing chemical contaminants and bad smells, everything from formaldehyde to shoe odor. According to an EPA study called "Ozone Generators that are Sold as Air Cleaners," they lack the approval of any federal agency and may do more harm than good, especially in homes of those with chronic respiratory problems.

What is Ozone? Why is it Harmful?

• Ozone is a molecule containing three oxygen atoms. Two of those atoms make up the helpful oxygen we breathe (O2), and the third atom makes ozone (O3). According to the EPA, the third oxygen atom can detach from the molecule, reattach itself to other molecules and alter their behavior. Its potential effect on other molecules is what leads ozone generator manufacturers to claim that ozone is a sort of super oxygen, able to purify air and water and even supercharge olive oil.

  Far above earth, in the stratosphere, ozone is protective and helpful, but it can have negative effects on humans in the atmosphere (where we live). The EPA has a saying that goes, "good up high, bad nearby," to illustrate this point. Ozone's traveling atom can react unpredictably with other molecules indoors and out, which is why ozone generators are not recommended, especially for indoor use.

  High levels of ozone cause lung irritation, asthma attacks, generally worsen chronic respiratory illnesses, and compromise the body's ability to fend off and recover from respiratory infections.

What is an Ozone Generator?

• An ozone generator produces ozone, which is a toxic gas. The idea behind an ozone generator is that it will render any chemical contaminants harmless by producing a chemical reaction whose only by-products are carbon dioxide, oxygen and water. The EPA gathered information from several peer-reviewed scientific studies to refute the claims of ozone generator manufacturers. They conclude that while reactions with common indoor elements may take place, they may take months or years to do so, that these machines do not remove carbon dioxide or formaldehyde (one study was conducted in a funeral parlor embalming room), that they do not remove particles from the air, and that some reactions may in fact be harmful. This should not be too surprising, considering that on the EPA's list of the six most common pollutants, ozone is at the top of the list.

  As for the machines themselves, some of them are equipped with an ozone regulator that allows the user to determine the amount of ozone they emit into the home. These regulators, the EPA found, are relatively ineffective, and the ozone output "is not proportionate to the control setting." In addition to these faulty regulators, manufacturers recommend purchasing and using in a small space a machine meant for a larger space. When the machines are used in a relatively enclosed area---where doors are periodically opened and closed---with a ventilation system periodically turned on and off, ozone levels were found to be far above the .05 parts per million that the EPA deems safe for humans. If the machines are run on a lower setting with interior doors open, the EPA found that ozone concentrations did not exceed public health standards. The ozone levels they reported did not include any ozone that might enter the home from the outdoors, meaning that those high levels could actually be even higher.

Other Methods

• There are other--more effective--ways to control your home's air quality. These machines--as well as other machines that are meant to remove allergen particles to clean indoor air--are often expected to work on their own without additional housekeeping methods being employed. The way to clean the air in your home is to locate and eliminate, if possible, the source of the indoor pollutant. Ventilation is the next most effective solution, and often involves the use of exhaust fans at the pollutant source, as well as other methods to divert and exhaust pollutants through outdoor air ventilation, provided the outdoor air is of good quality. The next best control method---to be used in conjunction with the other two---is air cleaning with an ionizer or electrostatic precipitator. These machines also emit a small amount of ozone, but never greater than .05 parts per million. However, the EPA notes that the effectiveness of these machines varies widely.