In-House Filtration Efficiency Assessment of Vapor Hydrogen Peroxide Decontaminated Filtering Facepiece Respirators (FFRs).

Khaled Al-Hadyan,Rashed Alhmaid,Ghazi Alsbeih,Belal Moftah,Jeffrey Lindstrom,Sawsan Falatah,Ahmad Nobah,Salem Al-Ghamdi,Nawarh Faran

doi:10.3390/ijerph18137169

Abstract

To cope with the shortage of filtering facepiece respirators (FFRs) caused by the coronavirus disease (COVID-19), healthcare institutions have been forced to reuse FFRs using different decontamination methods, including vapor hydrogen peroxide (VHP). However, most healthcare institutions still struggle with evaluating the effect of VHP on filtration efficiency (FE) of the decontaminated FFRs. We developed a low-cost in-house FE assessment using a novel 3D-printed air duct. Furthermore, we assessed the FE of seven types of FFRs. Following 10 VHP cycles, we evaluated the FE of KN95 and 3M-N95 masks. The 3M-N95 and Benehal-N95 masks showed significant lower FE (80.4–91.8%) at fine particle sizes (0.3–1 µm) compared to other FFRs (FE ≥ 98.1%, p < 0.05). Following 10 VHP cycles, the FE of KN95 masks was almost stable (FE stability > 99.1%) for all particle sizes, while 3M-N95 masks were stable only at 2 and 5 µm (FE stability > 98.0%). Statistically, FE stability of 3M-N95 masks at 0.3, 0.5, and 0.7 µm was significantly lower (p ≤ 0.006) than 2 and 5 µm. The in-house FE assessment may be used as an emergency procedure to validate the decontaminated FFRs, as well as a screening option for production control of FFRs. Following VHP cycles, both masks showed high stability at 5 µm, the size of the most suspected droplets implicated in COVID-19 transmission.

Highlights

The Friedman repeated measures analysis of variance on ranks showed that the overall median Filtration Efficiency (FE) values for6 of the and Benehal-N95 masks were significantly different from the N99/N95 SpectraShield mask (p < 0.05, respectively) with no other significant differences observed
The in-house FE assessment seems less restrictive than the National Institute for Occupational Safety and Health (NIOSH) FE. Method, it may have a potential benefit as an emergency procedure to validate the FE of decontaminated filtering facepiece respirators (FFRs) where the NIOSH method is unavailable
FE assessment can be used as a screening option for production control of FFRs as it is faster and cheaper than the standardized procedures.The KN95 mask showed higher FE stability than 3M-N95 masks at small particle sizes (0.3–2 μm) following vapor hydrogen peroxide (VHP) cycles

Summary

Introduction

The rapid increase in novel coronavirus disease (COVID-19) patients caused a dramatic global shortage of filtering facepiece respirators (FFRs), in particular, N95 masks [1,2]. The. N95 mask is a single-use respirator that can, when fitted correctly, block up to 95% of as small as 0.3 μm or larger particles. The N95 masks are approved by the US Food and. Drug Administration (FDA) and by the USA National Institute for Occupational Safety and Health (NIOSH) [3,4]. The FFRs, including N95 masks, are considered a critical component of infection prevention and control by decreasing COVID-19 transmission from patients to health care professionals. N95 masks are designed for single usage, and in cases

Results

Discussion

Conclusion