Ozone: A Novel Sterilizer for Personal Protective Equipment

Area of Science:

• Public Health
• Microbiology
• Environmental Science

Background:

• Personal protective equipment (PPE) scarcity during public health crises like COVID-19 impacts patient care and healthcare worker safety.
• Mandatory mask policies led to PPE reuse and bulk purchasing, exacerbating shortages.
• Current sterilization methods for N95 masks are insufficient or inaccessible for widespread use.

Purpose of the Study:

• To investigate the efficacy of a cost-effective ozone sterilization unit for decontaminating N95 masks.
• To assess the safety of using ozone sterilization units, particularly for home use.
• To provide an alternative sterilization method to address PPE scarcity.

Main Methods:

• N95 mask fabric was exposed to a surrogate virus (Escherichia coli bacteriophage MS2).
• Sterilization was performed using an ozone unit at approximately 30 ppm for 60 or 120 minutes.
• Viral plaque assays quantified viable virus post-sterilization, and ozone exposure levels were measured for safety assessment.

Main Results:

• A 120-minute ozone sterilization cycle achieved a 3-log reduction in viral activity, meeting U.S. Food and Drug Administration (FDA) standards.
• Ozone exposure levels during operation of the sterilization unit complied with federal and industry safety standards.
• The study demonstrated the potential for effective and safe decontamination of N95 masks.

Conclusions:

• Ozone sterilization presents a viable and safe method for decontaminating N95 masks.
• This approach can help mitigate PPE shortages during public health emergencies.
• Further research into ozone's potential for decontaminating other types of PPE is warranted.