It is understood that 254 nm UVC poses risks to humans over-exposed to it. With long enough exposure it can severely irritate eyes and skin reminiscent of too much sun exposure. Unlike sun exposure that is principally from UVA and UVB, UVC penetrates a little but not far enough to reach the cancer forming layers of skin. 254 nm UVC poses some more risk to eyes than does 222 nm. These observations are moot however if, in use, 254 nm UVC never strikes humans. FARLITETM has discovered that striking humans is unnecessary and avoids it.
UVC 222 nm light has a much shorter wavelength. This gives it the ability to break apart oxygen molecules that recombine with other oxygen molecules to create ozone. This is a known hazard associated with UVC light with any wavelength shorter than 230nm. The level of ozone produced is low but the production is continuous. UVC 254 nm light's wavelength cannot produce ozone.
Filtered UVC 222 nm light attacks and damages proteins as opposed to damaging reproductive elements. UVC 254 nm light attacks and damages the pathogen's DNA, essential to reproduction and spread. Thus, these two very similar approaches are slightly different -- and both are effective. It is true that Farlite'sTM technology can use either 222 nm or 254 nm in its UVPhasors. There are times that UV 222 better addresses inactivation requirements just as UV254 seems more effective in the upper-air. Farlite™ supports both in their appropriate situations.