The effect of ethanol immersion on fit performance and comfort of a fit tested reusable mask

Reusable high-filtration mask could be a solution for the global demand of disposable N95 and the environmental problems caused during a pandemic. We evaluated the effect of ethanol cleaning on the fit performance and comfort rating of Totobobo Masks, a reusable high-filtration mask. Healthy volunteers underwent quantitative fit testing with the Totobobo mask using a PortaCount Plus respirator fit tester. Fit factor ≥100 was considered adequate fit. Masks were then cleaned in 70% ethanol and air drying. Volunteers underwent a second and third fit test after each 15 cycles of ethanol cleaning. The proportion of adequate fit for Totobobo masks and overall fit factor were compared before and after each clean. Forty nine participants were recruited, of which 22/49 (44.9%) achieved adequate fit with Totobobo mask on the first fit test. Subsequently, 17/22 (77%) and 9/17 (53%) participants achieved adequate fit during the second and third fit tests, respectively. Proportion of adequate fit was similar before and after the first 15 cycles of ethanol cleaning ( p = .063) but lower after the second 15 cycles of ethanol cleaning ( p = .008). Fit factor was similar between the first and second fit tests ( p = 0 .808) and the second and third fit tests ( p = .125). Twenty out of 22 rated the Totobobo mask more comfortable than commercially available N95 masks. All participants rated the comfort level as either better or similar before and after cleaning. There is no significant drop in fit performance and comfort of Totobobo mask with up to 15 cycles of cleaning with 70% ethanol.