Have you had doubts about the safety of reusing decontaminated N95 masks? A new study tested four methods of sanitization to determine if they could safely be reused. Read on to learn more about the study results.
NursesCOVIDNews
The unprecedented shortage of personal protective equipment (PPE) is an unsafe burden placed on healthcare workers. To protect ourselves against the highly contagious coronavirus, N95 masks are essential in stopping the virus droplets from entering through our mouth and nose. Unfortunately, the worldwide pandemic has the healthcare industry struggling to extend the use of their current N95 supplies. To be used safely, the masks are generally designed for a single-use. However, workers are having to use the same mask over multiple shifts, adding to their risk of COVID-19 infection.
Putting Sanitization to the Test
Robert Fischer, PhD, with the National Institute of Allergy and Infectious Diseases in Montana, along with his colleagues, conducted a study to compare four methods of mask decontamination to determine which is the most effective. Specifically, the researchers compared the rate that SARS-CoV-2 virus is eliminated on the filter fabric of an N95 mask to virus decontamination on stainless steel. The methods used included:
Vaporized Hydrogen Peroxide (VHP)
Dry heat
UV lighting
Ethanol
After 3 uses, the masks were tested again to see if they maintained an effective fit and seal. Laboratory volunteers wore the decontaminated masks for 2 hours before testing fit.
Finding a Reliable Method
The researchers found that all four methods removed detectable SARS-CoV-2 virus from the mask's fabric. However, they did find the following variations among the four methods.
VHP
Fastest decontamination time (10 minutes)
Could be used up to 3 times and function properly
Dry heat
Required 60 minutes for decontamination
Could be used up to 2 times and function properly
UV lighting
Required 60 minutes for decontamination
Could be used up to 3 times and function properly
Ethanol
Not recommended
Mask did not function properly after decontamination
Currently, UV light and VPH are the most widely used methods for decontamination. UV light has been used for years to disinfect hospital rooms, making it easily accessible. And, hydrogen peroxide has continued to be available without extreme shortages.
Study Limitation
The researchers tested disinfected N95 masks after clinicians wore the mask for only 2 hours. However, we know that N95 masks are worn for much longer periods of time.
FDA Emergency Use Authorizations
On March 28, 2020, the FDA issued an Emergency Use Authorization (EUA), at Battelle Memorial Institute, to allow decontamination of N95 masks using a VPH method. Since then, EUAs have also been issued for Steris V-PRO system and STERRAD systems, with both using VPH method for sterilization.
CDC Recommendations for Decontamination
According to the CDC, only manufacturers can reliably provide procedures for decontamination without impacting t performance. Also, the CDC doesn't recommend N95 masks be decontaminated for reuse as a standard practice. However, the agency does recognize the pandemic is a time of crisis and options for disinfecting may need to be considered when N95 masks are in short supply.
CDC Recommendations for Reuse
The CDC has approved wearing the same N95 mask for repeated patient contact without removing the mask between patients. The approval is only for periods of crisis, such as pandemics, when mask supplies become scarce. The CDC has published the following Guidelines for Wearing N95 Masks for an Extended Period of TIme.
Discard N95 respirators after a patient has an aerosol procedure
Discard if contaminated with bodily fluids
Discard after close contact with any patient co-infected with an infectious disease requiring contact precautions
Consider using a cleanable face shield over an N95 respirator when feasible
Hand used respirators in a designated storage area or keep in a clean, breathable container, such as brown paper bags.
Clean hands after touching or adjusting the respirator
Avoid touching the inside of a respirator.
If contact is made with the inside, discard the respirator and perform hand hygiene
Use a pair of clean gloves with donning a used mask
More Research Needed
Healthcare workers understandably have reservations about wearing respirators that have been decontaminated. N95 masks will continue to be in short supply with the evolving pandemic. To ensure the safety of patients and workers, additional research is needed to evaluate procedures for both extended and reuse of respirators.
I work in a facility that is now reusing N95 masks and many workers are leery of this practice. What has been your experience?
