Believe it or not, not all air cleaning devices are appropriate for home use – some air purifiers emit ozone that can be harmful to your health. Air purifiers are ineffective if they are producing ozone in your home as they work to purify air. Ozone is a molecule composed of three atoms of oxygen. Two atoms of oxygen form the basic oxygen molecule that is essential to the air we breathe. The third oxygen molecule can re-attach to molecules of other substances and alter their chemical composition. Ozone is an important ingredient of smog and is a highly reactive and unstable gas. When inhaled, ozone can damage the linings of the respiratory tract. Symptoms include chest pain, coughing, shortness of breath and throat irritation. Ozone is especially harmful for those with chronic respiratory diseases such as asthma and compromise the ability of the body to fight respiratory infections. Which air purifiers should I avoid? It is important to avoid ozone generators and ionizing air purifiers.

These air purifiers send out a stream of negative ions that attract pollutants and become too heavy to remain airborne. The contaminants are removed from the air but do not leave the room and are not captured on the air purifiers collection plates or filters. They fall to the floor, land on walls, and are easily put back in the air. Ozone generators and ionizing air purifiers would be very effective if they did not pose a health threat. The biggest factor about these air purifiers is the ozone that they emit. The EPA has warned consumers against using ozone generators, and states in recent experiments ionizers were found to be less effective in removing particles of dust, tobacco smoke, pollen, or fungal spores than high efficiency particle filters (HEPA). What other methods can be used to control indoor air pollution? The concentration of ozone would have to greatly exceed health standards to be effective in removing most indoor air contaminants. In the process of reacting to chemicals indoors, ozone can produce other chemicals that themselves can be irritating and corrosive.

Although some reviews say that the ozone produced by electrostatic air cleaners is safe for those in normal good health, both the EPA and American Lung Association advise against using these devices, because there are many ozone-free high-efficiency particulate arresting (HEPA) models on the market. It is advised to use proven methods of controlling air pollution. Read Next: Different Types of Air PurifiersChildren, older adults, adults who are active outdoors, and people with respiratory diseases are most likely to be harmed by high levels of ozone. Some people who don't fall into any of these categories are apparently more sensitive to ozone and also suffer problems. The best way to protect your health is to find out when ozone levels are forecasted to be elevated in your area and take simple precautions to minimize exposure, even when you do not feel obvious symptoms. Pay attention to the air quality forecast, particularly in hot weather. Also visit this link for information on getting the forecast by email, RSS feed, Twitter, and through EPA's "AIRNow" free smart phone app. Local weather reports and other media outlets also report the forecast.

Based on the US EPA's Air Quality Index, the forecast uses an easy-to-understand color scale — with green being good and graduating colors from yellow to orange to red to purple to indicate the potential for problems. air purifier for growing mushroomsLearn more about the EPA Air Quality Index (AQI).gt 3000 air purifier review You should plan your days around these forecasts. zep ac coil cleaner msdsYou should also plan your children's days around these forecasts. On days when the forecast isn't good, you should minimize your exposure between 12:00 noon and 7:00 p.m., when ozone levels are highest. This is especially important for sensitive individuals. Even healthy adults should think twice about jogging in afternoons on code orange or worse days.

The North Carolina State Health Director has issued several warnings alerting consumers that certain types of indoor air cleaners can generate potentially harmful concentrations of ozone. These air cleaning devices are known as ozone-generating air purifiers. They are also marketed as "energized or activated oxygen" or "pure air" devices. The ozone generated by such devices is the same chemical that is responsible for the outdoor air pollution warnings issued in North Carolina during summer months. The manufacturers of ozone-generating devices provide room-sizing guidelines and some units are equipped with ozone-limiting sensors. However, controlled studies have shown that ozone concentrations from some of these devices can exceed acceptable public health standards. Independent research on ozone has shown that at concentrations below public health standards, the effectiveness of ozone to control indoor air pollutants is limited. Also, some electronic air cleaners, such as ion generators and electrostatic precipitators, may emit low levels of ozone as a by-product.

Owners should operate and maintain these air cleaners following manufacturer's instructions to reduce the potential for excess ozone generation. Any amount of ozone emitted into the indoor environment could potentially result in increased levels of reactive compounds and ultrafine particles due to reactions with fragrance compounds or other modern consumer products. A detailed summary on the ozone generator issue may be found at the United States Environmental Protection Agency's (EPA) Indoor Air Quality Web Site. The North Carolina Department of Health and Human Services (NC DHHS) has serious concerns about ozone exposures from these devices. The EPA and industrial hygienists with the NC DHHS advise the public to use other proven methods for controlling indoor air pollution. These methods include eliminating or controlling pollutant sources, increasing outdoor air ventilation, and using proven methods of air cleaning. For more information on indoor environmental quality issues, including ozone generators, please contact the Occupational and Environmental Epidemiology Branch at (919) 707-5900.