A Scalable Method of Applying Heat and Humidity for Decontamination of N95 Respirators During the COVID-19 Crisis

Loïc Anderegg; Cole Meisenhelder; Chiu Oan Ngooi; Lei Liao; Wang Xiao; Steven Chu; Yi Cui; John M Doyle

To test whether any degradation of the masks occured, we measure the filtration efficiency after five decontamination cycles. This number of cycles was chosen as previous reports, which also considered the 3M 1860, have shown that in the absence of any decontamination treatment five cycles of donning can be performed safely before fit tests began to fail consistently [16] . We tested the 3M 1860 1 surgical N95, 3M 8210 Plus N95, Chen Heng V9501 KN95 2 , and a HKYQ N95 3 . We perform quantitative fit test measurements after each decontamination cycle. We used a separate batch of masks for the filtration and fit tests as the masks used for fit testing must be modified to adapt to the fit testing apparatus and are worn by a user.