Efficacy and Safety of Disinfectants for Decontamination of N95 and SN95 Filtering Facepiece Respirators: A Systematic Review

Abstract
Background:
Decontaminating and re-using filtering face piece respirators (FFR)for healthcare workers is a potential solution to address inadequate FFR supply during a global pandemic.

Aim:The objective of this review was to synthesize existing data on the effectiveness and safety of using disinfectants to decontaminate N95 FFR.

Methods:
We conducted a systematic review on disinfectants to decontaminate N95 FFRs using Embase, Medline, Global Health, Google Scholar, WHO feed, and MedRxiv. Two reviewers independently determined study eligibility and extracted and verified predefined data fields. Original research reporting on N95 FFR function, decontamination, safety, or mask fit following decontamination with a disinfectant was included.

Findings and Conclusions:
A single cycle of vaporized H2O2 successfully removes infectious pathogens without affecting mask function or fit, and with little change in FFR physical appearance. Residual hydrogen peroxide levels following decontamination were below the safety limit. More than one decontamination cycle of vaporized H2O2may be possible but further information is required on how multiple cycles would affect mask fit in a real world setting before the upper limit can be established. Although immersion in liquid H2O2does not appear to adversely affect mask function, there is no available data on its ability to remove infectious pathogens from FFRs or its impact on mask fit. Sodium hypochlorite, ethanol, isopropyl alcohol and EtO are not recommended due to safety concerns or negative effects on mask function.