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

is the (which was not peer-reviewed) The copyright holder for this preprint Table 1 for respirator details) were inoculated with each of three viral species. These viruses represent a range of virion types and characteristics (see Table 2 for virus details), thus demonstrating the relative ability of aHP to inactivate many different viruses. The input inoculum for each virus was set to the maximum available in each viral stock preparation. HSV-1 and CVB3 showed a greater loss of infectiousness (plaque forming units, or PFU) due to drying than phi6. All virus species were inactivated by aHP. During optimization of aHP procedures, one cycle with short dwell time resulted in a failure of commercial spore-based biological indicators; indicating that aHP levels did not reach a sufficient level for full decontamination on that cycle. On this day 3 virus-inoculated sites were also positive (plotted in red, for ease of comparison), although other viral spots were still inactivated by the partial H2O2 decontamination. The dashed horizontal line indicates the limit of detection at 1 viral plaque. For the purposes of illustrating the disinfected samples where zero plaques were detected, these numbers were replaced with fractional values (e.g. 0.1), to allow their visualization on the logscale plot.