Use, reuse or discard: quantitatively defined variance in N95 respirator integrity following vaporized hydrogen peroxide decontamination during the COVID-19 pandemic

Abstract

Background: COVID-19 has stretched the ability of many institutions to supply needed personal protective equipment, especially N95 respirators. N95 decontamination and reuse programs provide one potential solution to this problem. Unfortunately, a comprehensive evaluation of the effects of decontamination on the integrity of various N95 models using a quantitative fit test (QTFT) approach is lacking. Aims: 1) To investigate the effects of up to eight rounds of vaporized H2O2 (VHP) decontamination on the integrity of N95 respirators currently in use in a hospital setting. 2) To examine if N95 respirators worn by one user can adapt to the face shape of a second user with no compromise of integrity following VHP decontamination. Methods: The PortaCount Pro+ Respirator Fit Tester Model 8038 was used to quantitatively define the integrity, measured by fit, of N95 respirators following decontamination with VHP. Findings: There was an observable downward trend in the integrity of Halyard Fluidshield 46727 N95 respirators throughout eight cycles of decontamination with VHP. The integrity of 3M 1870 N95 respirators was significantly reduced after the respirator was worn, decontaminated with VHP, and then quantitatively fit tested on a second user. Furthermore, we uncovered inconsistencies between qualitative fit test and QTFT results that may have strong implications on the fit testing method used by institutions. Conclusions: Our data revealed variability in the integrity of different N95 models after VHP decontamination and exposed potential limitations of N95 decontamination and reuse programs.

Decontaminating N95 respirators during the COVID-19 pandemic: simple and practical approaches to increase decontamination capacity, speed, safety and ease of use

“…Our study describes a more efficient way to perform the decontamination process. We have also confirmed that most but not all models of N95 respirators will continue to fit and function properly for at least six decontamination cycles [ 14 ]. This has also been confirmed by others using a single N95 respirator model [ 15 ].…”

“…The integrity of N95 respirators must be maintained following decontamination to prevent distribution of inadequate PPE from respirator reuse programs. We observed a downward trend in the functional integrity of Halyard Fluidshield N95 respirators throughout eight VHP decontamination cycles [ 14 ]. These data bring to light a potential liability of decontamination and reuse programs and warrant further study.…”

“…Quality control : At the end of each decontamination cycle, the PortaCount Pro+ Respirator Fit Tester Model 8038 was used to quantitatively define functional filtration integrity of the N95 respirators. Structural integrity was also evaluated via visual inspection of N95 respirators [ 14 ]. N95 respirators in the control rack underwent twelve decontamination cycles and were inspected after each run to determine if there was loss in respirator integrity, the results of the respirator integrity checks are described in a separate study [ 14 ].…”

Review of aerosolized hydrogen peroxide, vaporized hydrogen peroxide, and hydrogen peroxide gas plasma in the decontamination of filtering facepiece respirators

“… 20 Other studies were able to achieve a fit after 1, 6-8 (variance was dependent on mask model), or 10 cycles of vHP (Oral, Fischer, Unpublished Data). 10 , 22 , 23 However, Lieu et al . attempted to verify respirator fit after decontamination and real world use.…”

“… 24 Levine et al also found differences between different N95 models, both in the number of times they would pass fit testing post-vHP decontamination with the STERIS Victory (STERIS Corporation, OH, USA), as well as their ability to pass fit test post-decontamination when tested by a different wearer, a scenario which would likely occur if respirators are collected and redistributed to other healthcare workers under Tier 1 usage. 22 Recognizing these concerns, the FDA reissued a number of its EUAs, specifying that respirators may only be decontaminated for reuse a maximum of 4 times. 37…”