An air sanitizer is a sanitizer that acts on airborne microbiological organisms or microorganisms. In the United States, a sanitizer is a disinfectant that is intended to disinfect or sanitize, reducing or mitigating growth or development of microbiological organisms including bacteria, fungi or viruses on inanimate surfaces in the household, institutional, and/or commercial environment and whose labeled directions for use result in the product being discharged to publicly owned treatment works (POTWs).
Unlike air purifiers, which filter or otherwise trap particles within an air circulator, air sanitizers have the ability to act on airborne microorganisms in open interior air space. A sneeze- or cough-generated pathogenic aerosol will take significant time to be treated by a circulating air purifier simply because air circulators are unable to treat all air of the room simultaneously. Air circulators treat a fractional room volume per unit time and exhaust the treated air back into the room resulting in fractional air dilution. In contrast, air sanitizers that are maintained at a sufficient and homogeneous concentration (see homogeneous (chemistry)) within the interior air space provide simultaneous treatment of the entire interior air space volume, but are not able to remove particles including allergens. Air purifiers and air sanitizers are therefore complementary air treatment solutions. An air sanitizer is not an air freshener which add fragrance to the air and do not claim to act on microbiological organisms.
The vapors of some glycols including triethylene glycol can act as an air sanitizer. According to the United States Environmental Protection Agency, "There is considerable evidence that glycol vapors produce significant decreases in numbers of viable airborne bacteria under relatively wide conditions of relative humidity and temperature when properly and continuously dispensed by a vaporizing device so as to maintain suitable concentrations in the air in enclosed spaces."Glycol air sanitizers do not sterilize, disinfect, act as an antiseptic, or protect experimental animals from infections by airborne bacteria or viruses. Therefore, no health claims are allowed by manufacturers of such products. Also, currently no scientific evidence for the products claimed efficacy has to be provided by the manufacturer in the US