Just to add a bit to Mike's post - I've been looking at a pre publication paper from our Cousins (Boston University) that trialed specifically 254nm at 22mJ/cm2 on SARS-CoV-2 - which had an effective reduction on surface bacteria of 99.99999% exposed for 25 seconds.


The same wavelength and radiant energy density was effective at inactivating SARS-CoV-2 to a reduction of 99%, in air, when exposed for 6 seconds. The exposure duration is far to long for most air handling plant, so far higher radiant energy density will be needed to be useful in that format, but using UV-C as high level upper room air disinfection in occupied rooms could be quite effective for tackling aerosol virus particles.


At a room level, however, it's probably far easier to use better ventilation rates - if you achieve that, then using UV-C as well, is a law of diminishing returns.


For the phone and car keys issue, as Mike says, where the light shines you get disinfection, where it doesn't fall there is no disinfection. You'd be better of washing your hands and wiping the keys and phone in a decent hand sanitizer (or a drop of bleach)


Regards


OMS

Just to add a bit to Mike's post - I've been looking at a pre publication paper from our Cousins (Boston University) that trialed specifically 254nm at 22mJ/cm2 on SARS-CoV-2 - which had an effective reduction on surface bacteria of 99.99999% exposed for 25 seconds.


The same wavelength and radiant energy density was effective at inactivating SARS-CoV-2 to a reduction of 99%, in air, when exposed for 6 seconds. The exposure duration is far to long for most air handling plant, so far higher radiant energy density will be needed to be useful in that format, but using UV-C as high level upper room air disinfection in occupied rooms could be quite effective for tackling aerosol virus particles.


At a room level, however, it's probably far easier to use better ventilation rates - if you achieve that, then using UV-C as well, is a law of diminishing returns.


For the phone and car keys issue, as Mike says, where the light shines you get disinfection, where it doesn't fall there is no disinfection. You'd be better of washing your hands and wiping the keys and phone in a decent hand sanitizer (or a drop of bleach)


Regards


OMS