Analysis of SteraMist ionized hydrogen peroxide technology in the sterilization of N95 respirators and other PPE

Sci Rep. 2021 Jan 21;11(1):2051. doi: 10.1038/s41598-021-81365-7.


The COVID-19 pandemic has led to widespread shortages of personal protective equipment (PPE) for healthcare workers, including of N95 masks (filtering facepiece respirators; FFRs). These masks are intended for single use but their sterilization and subsequent reuse has the potential to substantially mitigate shortages. Here we investigate PPE sterilization using ionized hydrogen peroxide (iHP), generated by SteraMist equipment (TOMI; Frederick, MD), in a sealed environment chamber. The efficacy of sterilization by iHP was assessed using bacterial spores in biological indicator assemblies. After one or more iHP treatments, five models of N95 masks from three manufacturers were assessed for retention of function based on their ability to form an airtight seal (measured using a quantitative fit test) and filter aerosolized particles. Filtration testing was performed at a university lab and at a National Institute for Occupational Safety and Health (NIOSH) pre-certification laboratory. The data demonstrate that N95 masks sterilized using SteraMist iHP technology retain filtration efficiency up to ten cycles, the maximum number tested to date. A typical iHP environment chamber with a volume of ~ 80 m3 can treat ~ 7000 masks and other items (e.g. other PPE, iPADs), making this an effective approach for a busy medical center.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • COVID-19 / epidemiology
  • COVID-19 / prevention & control
  • Equipment Reuse / statistics & numerical data
  • Humans
  • Hydrogen Peroxide / pharmacology*
  • N95 Respirators / supply & distribution
  • N95 Respirators / virology*
  • Pandemics / prevention & control
  • Personal Protective Equipment / supply & distribution
  • Personal Protective Equipment / virology*
  • Respiratory Protective Devices
  • SARS-CoV-2 / isolation & purification
  • Sterilization / methods*
  • United States / epidemiology


  • Hydrogen Peroxide