Aerosolized Hydrogen Peroxide Decontamination of N95 Respirators, with Fit-Testing and Viral Inactivation, Demonstrates Feasibility for Re-Use During the COVID-19 Pandemic

Abstract

In response to the current urgent demand for N95 respirators by healthcare workers responding to the COVID-19 pandemic, with particular emphasis on needs within local medical systems, we initiated an N95 decontamination study using aerosolized hydrogen peroxide or aHP (7% H2O2 solution), via the Pathogo Curis® (Curis) decontamination system. The study has thus far included 10 cycles of respirator decontamination, with periodic qualitative and quantitative fit testing to verify ongoing respirator integrity through the decontamination process, and support a statistical evaluation of successful respirator fit. In addition, we have conducted virologic testing of respirator surfaces and materials to demonstrate a rigorous verification of decontamination.Given that the current pandemic entails a respiratory viral pathogen, it is critical to address these aspects of respirator safety for reuse. These measures are intended to provide a foundation for a suitable decontamination process, which maintains N95 function, and supports safe respirator reuse by healthcare providers. Current results from both respirator fit testing and virologic testing indicate that the process is effective on the basis of zero failure rate on fit-testing of selected respirators, and on complete decontamination of multiple virus species by aHP treatment, comparable to that observed with commercial spore-based biological indicators of sterilization.

A systematic review of mask disinfection and reuse for SARS-CoV-2 (through July 10, 2020)

“…The results from the eight H1N1 results 33,38,63,65 were presented in log reduction ranges, not specific log reductions, which precludes analysis herein. In the eight Phi6 results 27,40,56,72 , moist heat at 72-82°C for 30 minutes achieved <6 or >6 log reduction but inaccurate humidity readings occlude results, 7% aerosolized hydrogen peroxide had >6 log reductions with 30 minute exposure, and VHP at 16 gram/minute had >4 log after 30-40 minute exposure time; please note UVGI for one minute had only 1.5 log reduction. In the six IAV samples 41,43,56,63 , ozone removed 1-2 log after 40 minute exposure to 20 ppm, and moist heat and MGS achieved >3 log reduction after 30 minutes exposure to 60-82C moist heat for 30 minutes and 2 minute exposure to MGS.…”

“…Hydrogen peroxide disinfection (n=20) 15,19,27,29,30,36,45,51,57,[59][60][61]68 , dry heat (n=19) 12, 16, 19, 21, 29, 33-35, 42, 45, 49, 50, 52, 54 , UVGI (n=13) 15,16,29,35,42,45,46,52,[59][60][61][62] , and ethylene oxide (n=5) 19,[59][60][61] all had promising results.…”

Exploring options for reprocessing of N95 Filtering Facepiece Respirators (N95-FFRs) amidst COVID-19 pandemic: a systematic review

“…The copyright holder for this preprint this version posted September 3, 2020. ; https://doi.org/10.1101/2020.09.01.20179879 doi: medRxiv preprint reprocessing method: parameter combination. As we write this review, a large body of literature on reprocessing of N95-FFRs has been already published till 30 th June 2020 [44][45][46][47][48][49][50][51][52][53][54][55][56][57][58]. but when we did literature search, only few studies were published [44,45,49,58] and majority were in preprint, non-peer reviewed versions.…”

Hydrogen Peroxide Methods for Decontaminating N95 Filtering Facepiece Respirators

“…Multiple studies 7,8,12,13,15,18 have demonstrated that N95 FFRs inoculated with SARS-CoV-2 or other organisms can be effectively inactivated with proper use of decontamination systems that generate vapor from H 2 O 2 . However, dosing protocols are complex and could result in incomplete decontamination.…”

“…The only study of HPGP (STERRAD 100NX applied for a standard 47-min cycle) on FFRs (3M 1860S) inoculated with virus found that it inactivated VSV on all cutouts. 6 Derr et al 15 evaluated viral decontamination using the Curis AHP system (room volume 48 m 3 ) on five models of N95 FFRs (3M 1860, 1870+, 8511, 9211+, and Honeywell Sperian N11125) inoculated with herpes simplex virus 1, Coxsackie virus B3, and phage phi6. By the time the treatment had inactivated the biological index (G. stearothermophilus), all viruses were similarly inactivated to >6 log.…”