AB186. SOH21AS228. Microbiological safety of filtering facepiece respirator sterilisation using vapour hydrogen peroxide
General Poster Session

AB186. SOH21AS228. Microbiological safety of filtering facepiece respirator sterilisation using vapour hydrogen peroxide

Mihai Claudiu Rotaru1, Rossa Devlin1, Cliona NicGabhann1, German Pozdeev2, Hannah McMahon3, John Gibbons1, John Martin O’Byrne1, Steven Kerrigan2

1Department of Trauma and Orthopedics, National Orthopedic Hospital Cappagh, Dublin, Ireland; 2School of Pharmacy and Biomolecular Sciences, RCSI University of Medicine and Health Sciences, Dublin, Ireland; 3Clinical Decontamination Unit, National Orthopaedic Hospital Cappagh, Dublin, Ireland

Background: The COVID-19 pandemic highlighted the risk of filtering face-piece respirator (FFR) shortage at hospital level leading to a potential for significant rates of infection amongst frontline healthcare workers. To circumvent such shortage, extending the lifespan of FFR by means of decontamination and re-use was suggested. The aim of this study is to validate the use of vapour hydrogen peroxide (VHP) in the decontamination of facial personal protective equipment (PPE) through mechanical and biological analysis.

Methods: VHP capability to inactivate pathogens was assessed using experimentally inoculated masks. FFRs were contaminated with clinical strains of bacteria (gram negative: Escherichia coli & gram positive: Staphylococcus aureus), fungus (Candida albicans) and virus (SARS-CoV-2). Infection post-sterilization was determined via colony forming units. SARS-CoV-2 detection with q-PCR using primers and probes recommended by Centre for Disease Control and Prevention and World Health Organisation.

Results: The infected control mask contained 1.7×105 colony forming units colony forming units CFU’s/20 µL of Staphylococcus aureus and 1×105 CFU’s/20 µL of E. coli. Following VHP sterilization there was no detectable bacteria on the masks (P=0.0006, n=3). Similarly, fungus was detectable in control masks 1×106 CFU’s/20 µL, however following VHP sterilization it was not detectable (P<0.0008, n=3). SARS-CoV-2 was detectable in control masks (ct value 23–26 cycles), following VHP sterilization there was no detectable virus (ct >33 cycles) (P<0.0001, n=11).

Conclusions: VHP is an efficient decontamination method of used FFRs eradicating bacteria, fungus and virus (SARS-CoV-2) even after five cycles of usage. These data suggest that should there be a shortage of PPE in hospitals in the future, masks can be sterilized and re-used to protect the health of front line workers.

Keywords: COVID-19; decontamination; filtering face piece respirator (FFR); microbiological safety; SARS-Cov-2; vapour hydrogen peroxide


Funding: None.


Conflicts of Interest: The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

doi: 10.21037/map-21-ab186
Cite this abstract as: Rotaru MC, Devlin R, NicGabhann C, Pozdeev G, McMahon H, Gibbons J, O’Byrne JM, Kerrigan S. SOH21AS228. Microbiological safety of filtering facepiece respirator sterilisation using vapour hydrogen peroxide. Mesentery Peritoneum 2021;5:AB186.

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