The light is outside our visible spectrum. Specifically it measures 200-280nm and targets germicidal range which is not the same as the UVA and UVB used in tanning beds or sunlight exposure. Reference
You don’t want unprotected skin and eyes exposed to UVC light for very long. You can get your daily UV exposure in just 45 seconds.
UVC disinfects by disrupting the DNA and RNA in a cell or virus from replicating, and renders it unable to cause or spread infection.
Each of the Philips tubes are 55 watts and there are two in each B direct unit.
The B Direct fixture will disinfect roughly a 230 sq./ft. area at a distance of 8 feet.
Long exposure to UVC will deteriorate cheap plastics. White foam and low density foam like packing materials are susceptible to deterioration especially at long exposure. Acrylic plastics and others are developed to be UV resistant.
The air unit uses fans to move air in the room through a tube around UVC lamps. As the air moves around the lamp, it very quickly receives a significant dose of UVC and pushed out the other end, disinfected.