Is the fit of N95 facial masks effected by disinfection? A study of heat and UV disinfection methods using the OSHA protocol fit test

The current COVID-19 pandemic has highlighted global supply chain shortcomings in the US hospital delivery system, most notably personal protective equipment (PPE) and COVID-19 is found on these masks ∼7 days. Recent work from our group has shown two promising disinfection methods for N95 facial masks, dry heat (hot air (75 °C, 30 min) and UVGI which is UVGI 254 nm, 8W, 30 min. Using N95 five models of N95 masks from three different manufacturers we determined the following: 1) Hot air treated N95 masks applied over 5 cycles did not degrade the fit of masks (1.5% change in fit factor, p = .67), 2) UVGI treated N95 masks applied over 10 cycles were significantly degraded in fit and did not pass quantitative fit testing using OSHA testing protocols on a human model (−77.4% change in fit factor, p = .0002).