Each Airocide product has a fan that draws the air from your home into the unit. The air is slowly pushed across hollow glass tubes. These tubes are coated with what is called a catalyst. A catalyst is something that makes a chemical process easier. The name for this process is Photocatalytic Oxidation. It is safe, efficient, and has been proven to produce no harmful byproducts. This is the exact same process that NASA used as a VOC air purifier on the International Space Station.