HEPA air purifiers have been on the market for a while, but there have also been some recent advances made in air purification technologies. Many air purifier manufacturers are now utilizing Photocatalytic Oxidation (PCO) technology as a way of removing toxins from the air. This air purification method may be the most advanced one yet, and some leading air purifier manufacturers are beginning to add PCO air cleaners to their product lines.
For years, PCO has been FDA approved for reducing bacteria in meat processing plants, and it's even used to cleanse pesticides from the fruits and vegetables we eat. Essentially, PCO filtration can be summed up like this: An intense light is reflected onto a metal surface which in turns oxidizes toxins. In chemistry, photocatalysis is defined as the acceleration of a photoreaction in the presence of a catalyst. An example of this would be the oxidation of organic contaminants such as bacteria and mold using magnetic particles coated with titanium dioxide nanoparticles, and agitated using a magnetic field that is exposed to UV light. Therefore, this type of purification technology converts harmful particulates and toxic gases into safer compounds such as carbon dioxide and water.
PCO uses broad-spectrum UV light which reacts with a thin film of titanium dioxide, which, in the presence of water, creates hydroxyl radicals and super-oxide ions that "burn" VOCs and microorganisms absorbed on the catalyst's surface. With that in mind, many consumers may mistake UV air purification with PCO technology, and rightfully so. However, while both types of technology are similar in that they harness the oxidation properties of ultraviolet light, PCO purification systems utilize UV lamps with additional wavelengths. These additional wavelengths ensure a quicker reaction rate when it comes to the degrading of toxic compounds that are polluting the air you breathe.
Because PCO technology is an extremely powerful purification method, PCO units have the ability to eliminate particles as small as 0.001 microns, including the tiny penetrating particles that can absorb into your lungs and cause damage (HEPA filters are only able to filter out particles as small as 0.3 microns). Studies have also shown that in addition to VOCs, toxic gases, and chemicals, photocatalytic units can also render gases like carbon monoxide and nitrous oxide harmless -- these are pollutants which can often escape standard units utilizing HEPA or ionic technology alone.
Those concerned with the possible health effects associated with PCO will be glad to know that PCO units have been found to be much safer than ozone and ionization, and they work wonderfully well for those with asthma, allergies, and multiple chemical sensitivity. Nonetheless, one should keep in mind that minute levels of ozone are created during the catalytic free radical generation process, but most PCO purifiers only produce ozone levels in the 0.01 - 0.04 ppm range (0.05 ppm is the maximum level allowed by federal law for medical devices).
Author Profile: Jeanie Wong is a marketing writer with extensive knowledge of heating, cooling, and air purification systems.
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