UM researcher leads study on effective N95 mask decontamination during COVID-19 crisis

3-Apr-2020 12:30 PM EDT, by University of Manitoba

Newswise — University of Manitoba clinician-scientists and their research partners at Canada’s National Microbiology Laboratory (NML) have identified effective standard hospital sterilization techniques that may enable in-demand N95 masks to be sterilized up to 10 times for reuse in clinical settings.

The research, conducted by researchers at both Health Sciences Centre Winnipeg (HSC) and the NML in Winnipeg, was performed by a team of five researchers led by Dr. Anand Kumar, a UM researcher and critical-care physician at HSC, in response to worldwide concerns about the supply of N95 masks.

“Medical masks are used by health-care workers, with the N95 providing the best protection against tiny aerosol particles that carry the novel coronavirus. At the start of the pandemic, it was clear we were going to be facing dramatically heavy demands for the N95s,” said lead author Kumar, professor of medicine (critical care and infectious diseases), medical microbiology/infectious diseases and pharmacology/therapeutics at the University of Manitoba. “Our team wanted to explore how different brands and models of N95s responded to standard hospital sterilization technologies in an attempt to identify safe options for their reuse in the event of supply shortages.”


In mid-March, HSC physicians/faculty members at the UM’s Max Rady College of Medicine, worked with NML scientists to test four different types of N95 masks using four different sterilization methods: repeated cycles of standard autoclaving; ethylene oxide gassing; ionized hydrogen peroxide (iHP) fogging; and vaporized hydrogen peroxide (VHP) treatment.

In addition, the ability of all four decontamination techniques to totally eliminate viruses on the masks was tested.

Afterwards, these N95s were visually and tactilely assessed for structural integrity and underwent quantitative fit testing to assess functional integrity.

“Our results demonstrate that the assessed decontamination methods were highly effective in sterilizing all four contaminated N95 models mask types. No viable virus was found on any intentionally-contaminated mask following any of the decontamination procedures,” said Kumar, noting that in some cases the researchers used a non-pathogenic virus in place of SARS-CoV-2 virus (which causes COVID-19) and the study was not performed on masks worn by health-care workers. Further testing has been carried out at the NML, which used the SARS-CoV-2 virus to contaminate the masks, and results are expected in the near future.

Kumar’s initial study results indicated several of the decontamination methods could be used repeatedly without degrading the masks’ effectiveness so that the use of individual N95 masks could potentially be extended several-fold.

Kumar pointed to two sterilization methods which showed no loss of filtering function after multiple cleanings. However, one method, the vaporized hydrogen peroxide, is not widely available in North America.

“I’m particularly excited by the fact that autoclaving works on most masks because unlike the other techniques, it should be available at every established hospital in the world, including in the most poorly resourced countries,” he said, pointing to the commonly-used, pleated N95 masks as the type of mask that tolerates undergoing this sterilization process.
“We successfully decontaminated these pleated, fabric N95 masks up to 10 times using autoclaving,” he said, noting autoclaving equipment relies on high heat and steam to disinfect and sterilize.

The team’s goal is to share their research findings so that jurisdictions can assess the options that will enable their health-care workers to be appropriately protected.

“Many institutions in highly-affected regions of the world are running out of these masks and others are rationing so that health-care workers must make use of the same masks for long periods which can lead to mask failure and increased risk to the worker,” said Kumar, noting the study has not yet undergone peer-review or been published in a medical journal.

The full pre-review paper is available here

Filters close

Showing results

110 of 3765
Released: 23-Oct-2020 4:55 PM EDT
Woman recovering from COVID-19 shares experience as monoclonal antibody clinical trial participant
University of Texas Health Science Center at Houston

When Christina Loville tested positive for the coronavirus, she was terrified. She decided to channel her fear into researching COVID-19 treatments, where she discovered a local clinical trial led by experts at The University of Texas Health Science Center at Houston (UTHealth).

Released: 23-Oct-2020 4:30 PM EDT
"Third spike" in COVID-19 cases, plus the vaccine trials: Live Expert Panel for October 29, 3PM EDT

"Third spike" in COVID-19 cases, plus the vaccine trials: Live Expert Panel for October 29, 3PM EDT

Released: 23-Oct-2020 1:50 PM EDT
Are we really “rounding the corner" when it comes the coronavirus pandemic?

“We’re rounding the turn,” Trump said during the debate. This implies a meaningful improvement. We rate this claim as false. On that very same day the U.S. recorded 77,000 new cases, according to NBC News. This tops the previous high that had been set in July. We may be learning to "live with it," as Trump mentioned, but this is not an improvement.

Newswise: 246719_web.jpg
Released: 23-Oct-2020 12:50 PM EDT
NRL researchers evaluate ultraviolet sources, combat COVID-19
United States Naval Research Laboratory

U.S. Naval Research Laboratory researchers evaluated commercial ultraviolet (UV) sources for viral disinfection to combat COVID-19 on land and at sea, and established a dedicated UV characterization lab in five days to ensure safe introduction and effective operation of UV sources across the Fleet.

Released: 23-Oct-2020 12:05 PM EDT
COVID-19 anxiety linked to body image issues
Anglia Ruskin University

A new study has found that anxiety and stress directly linked to COVID-19 could be causing a number of body image issues amongst women and men.

Newswise: 246747_web.jpg
Released: 23-Oct-2020 11:45 AM EDT
Eliminating COVID-19: What the world can learn from NZ and Taiwan
University of Otago

Both Taiwan and New Zealand have successfully eliminated COVID-19 with world-leading pandemic responses. By taking a particularly proactive approach, Taiwan's response was probably the most effective and least disruptive of any country's, researchers say.

Released: 23-Oct-2020 11:00 AM EDT
Healthcare's earthquake: Lessons from COVID-19
Beth Israel Deaconess Medical Center

The COVID-19 pandemic has fundamentally disrupted U.S. healthcare organizations.

Released: 23-Oct-2020 10:50 AM EDT
COVID-19 lockdown reduced mental health, sleep, exercise
Pennington Biomedical Research Center

A first-of-its-kind global survey shows the initial phase of the COVID-19 lockdown dramatically altered our personal habits, largely for the worse.

Released: 23-Oct-2020 10:45 AM EDT
New Data on Increasing Cloth Mask Effectiveness
Society for Risk Analysis (SRA)

A new study published in Risk Analysis, “Reinventing cloth masks in the face of pandemics,” by Stephen Salter, P.Eng., describes how Effective Fiber Mask Programs (EFMPs) can help communities find a balance between the economy and curbing community spread.

Showing results

110 of 3765