N95 Respirators Can Be Reprocessed Using Vaporized Hydrogen Peroxide

Christina F. Yen, M.D., from Beth Israel Deaconess Medical Center in Boston, and colleagues examined whether repeated VHP reprocessing would affect the integrity of N95 respirators as defined by qualitative and quantitative fit and filtration efficiency over 25 reprocessing cycles.

The researchers found that all reprocessed N95 respirators met the primary end points of function and effectiveness. The respirators passed 25 user seal checks and eight quantitative and four qualitative fit tests; filtration efficiencies remained at 95 percent or higher. The initial filtration efficiency was 100 percent for particles between 0.3 and 0.375 µm and 99.95 percent for those 0.3 to 10 µm in diameter; at cycles 20 and 25, the mean filtration efficiency was 99.9 and 99.6 percent, respectively, for particles between 0.3 and 10 µm. Compared with initial filtration efficiency, there was no statistically significant change seen in filtration efficiency for cycle 20 or cycle 25.

"VHP reprocessing appears to be a safe, viable means to augment N95 respirator supply in future epidemics," the authors write. "However, successfully implementing large-scale reprocessing requires multidisciplinary teams to ensure disinfection efficacy and end-user safety, as well as significant logistical support."