Air Purifiers and Ozone There are many air purifiers available that do not produce ozone Some electronic air purifiers emit ozone, either intentionally or as a byproduct. Underwriters Laboratory Safety Standard 867 establishes 50 parts per billion as the maximum safe limit -- the same level that's been established by the U.S. Food and Drug Administration (FDA) as the maximum allowable ozone emissions for medical devices. The Association of Home Appliance Manufacturers (AHAM) does not independently test for ozone levels, but does post which of the air purifiers it lists are certified to meet UL standards. Ozone in large amounts can neutralize strong odors (such as the smoke odor from fire damage), but, according to the EPA, using an ozone air purifier can be dangerous for human health because ozone can cause lung damage, worsen asthma and cause other lung problems. "Relatively low amounts of ozone can cause chest pain, coughing, shortness of breath and throat irritation," according to the EPA.

"It may also worsen chronic respiratory diseases such as asthma as well as compromise the ability of the body to fight respiratory infections."a absolute air duct and carpet cleaning des moines Further, the EPA states that ozone levels that fall within safety standards are not effective in removing "indoor air contaminants" based on currently available scientific evidence. hunter quietflo air purifier manualIn addition, safe levels of ozone are not effective in "removing many odor-causing chemicals," nor can it "effectively remove viruses, bacteria, mold, or other biological pollutants."honeywell air cleaner f57a There are also concerns that even smaller amounts of ozone could be harmful over the long term.

A study published in The New England Journal of Medicine in March 2009 followed nearly 450,000 people in 96 U.S. cities from 1977 through 2000. It found that long-term exposure to low levels of outdoor ozone -- under the 50 ppb generally considered safe -- can be fatal. For every 10 ppb increase in ozone concentration, the risk of death from respiratory causes (primarily pneumonia and chronic obstructive pulmonary disease) went up 4 percent. That "can translate into thousands of excess deaths each year," says study lead author Michael Jerrett, a University of California-Berkeley associate professor of environmental health sciences. There have been a lot of studies on the health effects of outdoor ozone levels, but few long-term tests have measured the effects of ozone produced by indoor devices like ozone air purifiers or ionic air purifiers. One 2006 study published in the Journal of the Air & Waste Management Association tested 13 air purifiers, including several personal air cleaners designed to be in close proximity to the user.

Research analysts concluded that even these are capable of producing steady levels of indoor ozone that exceed health standards. Indeed, some people say they can smell ozone, and some report headaches. recommended some air purifiers that emit small amounts of ozone as a byproduct, but now editors say, "These products' performance has not changed significantly, but our advice has. We now believe that air purifiers that emit even small amounts of ozone (less than 50 ppb) are not your best choice." Although some reviews say that the ozone produced by electrostatic air cleaners is safe for those in normal good health, the EPA, American Lung Association and most other expert sources recommend against using these devices. California has banned the sale of air purifiers that exceed the UL standard of 50 parts per billion, though they can still be bought elsewhere. Good Housekeeping offers this blunt advice: "If you already own an air purifier, make sure it doesn't produce ozone and if it does, stop using it and cut the cord before you discard it so no one else can use it either."

Prev3 Best Air PurifiersCheap/Small Air PurifiersFurnace Filters and UV Air PurifiersBuying GuideOur SourcesNext A Sharp FU-888SV Plasmacluster air purifier. The same air purifier, cover removed. An air purifier is a device which removes contaminants from the air in a room. These devices are commonly marketed as being beneficial to allergy sufferers and asthmatics, and at reducing or eliminating second-hand tobacco smoke. The commercially graded air purifiers are manufactured as either small stand-alone units or larger units that can be affixed to an air handler unit (AHU) or to an HVAC unit found in the medical, industrial, and commercial industries. Air purifiers may also be used in industry to remove impurities such as CO2 from air before processing. Pressure swing adsorbers or other adsorption techniques are typically used for this. Dust, pollen, pet dander, mold spores, and dust mite feces can act as allergens, triggering allergies in sensitive people. Smoke particles and volatile organic compounds (VOCs) can pose a risk to health.

Exposure to various components such as VOCs increases the likelihood of experiencing symptoms of sick building syndrome.[1] Air purifiers are becoming increasingly capable of capturing a greater number of bacterial, virus, and DNA damaging particulates. Several different processes of varying effectiveness can be used to purify air. Other aspects of air cleaners are hazardous gaseous by-products, noise level, frequency of filter replacement, electrical consumption, and visual appeal. Ozone production is typical for air ionizing purifiers. Although high concentration of ozone is dangerous, most air ionizers produce low amounts (<0.05> ppm). The noise level of a purifier can be obtained through a customer service department and is usually reported in decibels (dB). The noise levels for most purifiers are low compared to many other home appliances.[] Frequency of filter replacement and electrical consumption are the major operation costs for any purifier. There are many types of filters;

some can be cleaned by water, by hand or by vacuum cleaner, while others need to be replaced every few months or years. In the United States, some purifiers are certified as Energy Star and are energy efficient. HEPA technology is used in portable air purifiers as it removes common airborne allergens. The US Department of Energy has requirements manufacturers must pass to meet HEPA requirements. The HEPA specification requires removal of at least 99.97% of 0.3 micrometers airborne pollutants. Products that claim to be "HEPA-type", "HEPA-like", or "99% HEPA" do not satisfy these requirements and may not have been tested in independent laboratories. Air purifiers may be rated on: CADR(Clean Air Delivery Rate); air changes per hour; the clean air delivery rate, which determines how well air has been purified; and the cost of the replacement filters. Two other important factors to consider are the length that the filters are expected to last (measured in months or years) and the noise produced (measured in decibels) by the various settings that the purifier runs on.

This information is available from most manufacturers. As with other health-related appliances, there is controversy surrounding the claims of certain companies, especially involving ionic air purifiers. Many air purifiers generate some ozone, an energetic allotrope of three oxygen atoms, and in the presence of humidity, small amounts of NOx. Because of the nature of the ionization process, ionic air purifiers tend to generate the most ozone.[] This is a serious concern, because ozone is a criteria air pollutant regulated by health-related US federal and state standards. In a controlled experiment, in many cases, ozone concentrations were well in excess of public and/or industrial safety levels established by US Environmental Protection Agency, particularly in poorly ventilated rooms. Ozone can damage the lungs, causing chest pain, coughing, shortness of breath and throat irritation. It can also worsen chronic respiratory diseases such as asthma and compromise the ability of the body to fight respiratory infections—even in healthy people.

People who have asthma and allergy are most prone to the adverse effects of high levels of ozone.[17] For example, increasing ozone concentrations to unsafe levels can increase the risk of asthma attacks. Due to the below average performance and potential health risks, Consumer Reports has advised against using ozone producing air purifiers.[18] IQAir, the educational partner of the American Lung Association, has been a leading industry voice against ozone-producing air cleaning technology. Ozone generators used for shock treatments (unoccupied rooms) which are needed by smoke, mold, and odor remediation contractors as well as crime scene cleanup companies to oxidize and permanently remove smoke, mold, and odor damage are considered a valuable and effective tool when used correctly for commercial and industrial purposes. However, there is a growing body of evidence that these machines can produce undesirable by-products. In September 2007, the California Air Resources Board announced a ban of indoor air cleaning devices which produce ozone above a legal limit.