New technique to evaluate decontamination methods for filtering facepiece respirators

Area of Science:

• Infectious Disease
• Public Health
• Biomedical Engineering

Background:

• N95 filtering facepiece respirator (FFR) shortages are a significant concern during pandemics.
• Decontamination and reuse of FFRs is a potential strategy to mitigate shortages.
• Developing effective decontamination methods requires meeting key criteria: viral inactivation, preservation of respirator properties, and absence of toxic byproducts.

Purpose of the Study:

• To evaluate ultraviolet germicidal irradiation (UVGI) and moist heat (MH) as decontamination methods for N95 FFRs.
• To assess the efficacy of UVGI and MH in inactivating viruses on FFRs.
• To determine if UVGI and MH alter FFR properties or leave toxic residues.

Main Methods:

• FFRs (hydrophilic and hydrophobic) were contaminated with MS2 virus using solution-based, vapor-based, and aerosol-based deposition.
• UVGI and MH decontamination methods were applied to the contaminated FFRs.
• Respirator properties and the presence of toxic byproducts were evaluated post-decontamination.

Main Results:

• Both UVGI and MH methods achieved significant viral inactivation, with >5-log reduction of MS2 virus.
• In 92% of experiments, viral levels were reduced below the detection limit.
• Neither UVGI nor MH altered the essential properties of the FFRs or introduced toxic byproducts.

Conclusions:

• UVGI and MH are promising methods for decontaminating N95 FFRs.
• These methods support the safe reuse of FFRs during public health emergencies and shortages.
• The study provides an evaluation technique based on viral inactivation, property preservation, and toxicity assessment.