Lighting designers will be familiar with the illuminance of a planar surface, which is measured in lumens per square meter (or foot). The irradiance of a planar surface by a germicidal radiation source is conceptually the same, except that it is measured in watts per square meter (W/m2). Most designers, however, will not be familiar with the...

There is a newcomer on the block that has gained considerable media attention: far-ultraviolet excimer lamps. Recent medical studies have indicated that, unlike 254 nm radiation, the 207 nm and 222-nm “far-UV” radiation emitted by excimer lamps is likely harmless (e.g., Buonanno et al. 2017, Welch et al. 2018). Excimer lamps have the same...