Some notes on “far UV-C” light

Can we use a new kind of UV-C light in occupied spaces?

In 1903, Niels Finsen was awarded the Nobel Prize for using UV-C light for disinfection, originally for lupus. Since then, UV-C has been used in tackling Tuberculosis and MRSA in hospitals.

Recent interest in UV-C for COVID-19 has involved disinfecting air (since there is potential for the virus to transmit via aerosols), and also for fast surface disinfection.

Historically, UV-C sources have mainly been 254nm lamps, a wavelength very good at destroying DNA/RNA. However, 254nm is not safe to use where people can see it, because it can hurt your cornea. While this kind of light will not make you blind, it hurts: it is described as a gritty feeling right after, with intense pain after that, until your cornea has a chance to regrow.

“Far” UV-C

Recently, work by David Brenner and colleagues at Columbia has included “far UV-C” light from 207–222nm, with 222nm the most promising.

Some additional notes about UV-C

For more information about UV-C disinfection (with actual experts), refer to the IES FAQ here.

co-founder of f.lux, finding the connections between circadian rhythms, sleep, healthy buildings, and light. (Previously made Picasa.)