Aerosolized Hydrogen Peroxide Decontamination of N95 Respirators, with Fit-Testing and Virologic Confirmation of Suitability for Re-Use During the COVID-19 Pandemic

T. Hans Derr; Melissa A. James; Chad V. Kuny; Prem P. Kandel; Matthew D. Beckman; Kevin L. Hockett; Mark A. Bates; Moriah L Szpara

Like SARS-CoV-1, SARS-CoV-2 has a high level of environmental stability (16) (17) (18) (19) (20) . In terms of virion characteristics, SARS-CoV-2 has a lipid enveloped virion of ~120 nm, with no icosahedral capsid core. The lipid envelope encloses a single-stranded, linear, positive-sense RNA genome (summarized in Table 2 ). We used multiple virus species to test the viral inactivation capabilities of aHP decontamination. These viruses represented multiple characteristics of human viral pathogens, with a range of virion types and sizes, genome types and lengths, and previously documented environmental stability (21) (22) (23) . Virions of herpes simplex virus 1 (HSV-1) and Pseudomonas phi6 bacteriophage have a lipid envelope, with an underlying icosahedral capsid core. In contrast, coxsackievirus B3 (CVB3) is a non-enveloped or naked icosahedral capsid virus. Prior work has shown that naked-capsid viruses have a higher stability than enveloped viruses, thus providing a useful test of aHP sterilization abilities (21) (22) (23) . While most viruses utilized in this study are mammalian viruses requiring analysis in mammalian cell lines at biosafety level 2 (BSL2), phi6 can be assayed more flexibly, using rapid bacterial cultures (24-hour turnaround) at biosafety level 1. Phi6 is a natural pathogen phage of Pseudomonas syringae pathovar phaseolicola, which is itself a bacterial pathogen of green beans. We found that all viral species examined in this study were effectively sterilized by aHP, comparable to the decontamination observed with commercial spore-based biological indicators of sterilization. Together, this combination of respirator fit testing and virologic testing suggest that aHP is a suitable decontamination process to enable reuse of N95 respirators during the COVID-19 pandemic.