Remember that book that I wrote on UV Photography? Well, I ended up collecting/building a number of UV lamps, and some of them emit UV-C. I set them up as a makeshift decontamination rack for our N95 masks.
The effectiveness of using germicidal (UV-C) light to decontaminate N95 masks to extend their useful time is well established. In fact, use of Ultraviolet Germicidal Irradiation (UVGI) has been recommended as an emergency measure by the CDC. The limiting factor is that UV-C degrades polymers, so it will eventually cause failure to the mask’s structural integrity (Lindsley et al, 2015).
Our protocol at home, based on my understanding of CDC’s guidelines and the intensity of my lights is to use masks for up to 8 hours (of actual use time when outside of the house grocery shopping or running essential errands) and then expose them for 15 minutes per side to UVGI before reuse.
IMPORTANT NOTE: This post should not be construed as advice on the decontamination of PPE. Please refer to official information on this matter from the CDC.
WARNING: Midrange and short-wave ultraviolet radiation can cause permanent eye and skin damage. Do not look directly at midrange or short-wave UV radiation, even for brief periods. Take appropriate precautions with pets and other living organisms that might suffer injury or damage due to UV exposure at these wavelengths.