N95 respirator decontamination: a study in reusability.

Area of Science:

• Microbiology
• Public Health
• Biomedical Engineering

Background:

• The COVID-19 pandemic led to critical shortages of N95 respirators globally.
• Effective decontamination methods are essential for N95 respirator reuse and supply chain resilience.

Purpose of the Study:

• To systematically evaluate five decontamination methods for N95 respirators.
• To assess the impact of decontamination on respirator integrity and performance.

Main Methods:

• Testing bioburden, filtration efficiency, fluid resistance, and fit of decontaminated respirators.
• Utilizing vaporized hydrogen peroxide (VHP) and ultraviolet germicidal irradiation (UVC) technologies.
• Evaluating decontamination cycles ranging from 2 to 15.

Main Results:

• Four VHP methods (BioQuell, custom container, Steris, Sterrad) achieved 3-log10 Cardiovirus and 6-log10 bacteria reduction without compromising respirator integrity.
• Hope UVC system demonstrated 3-log10 Cardiovirus inactivation but had weaker bactericidal activity.
• Decontamination batch sizes ranged from 10-1000 respirators with cycle times of 10-200 minutes.

Conclusions:

• VHP-based decontamination methods are safe and effective for multiple N95 respirator reuses.
• These validated methods support industrial, laboratory, and hospital applications, enhancing respirator availability.