Electric cooker an easy, efficient way to sanitize N95 masks, study
finds

Date:
August 6, 2020
Source:
University of Illinois at Urbana-Champaign, News Bureau
Summary:
A new study found that 50 minutes of dry heat in an electric cooker
decontaminated N95 respirators inside and out while maintaining
their filtration and fit. This could enable wearers to safely
reuse limited supplies of the respirators.



FULL STORY ========================================================================== Owners of electric multicookers may be able to add another use to its list
of functions, a new study suggests: sanitization of N95 respirator masks.


==========================================================================
The University of Illinois, Urbana-Champaign study found that 50 minutes
of dry heat in an electric cooker, such as a rice cooker or Instant Pot, decontaminated N95 respirators inside and out while maintaining their filtration and fit. This could enable wearers to safely reuse limited
supplies of the respirators, originally intended to be one-time-use items.

Led by civil and environmental engineering professors Thanh "Helen"
Nguyen and Vishal Verma, the researchers published their findings in
the journal Environmental Science and Technology Letters.

N95 respirator masks are the gold standard of personal protective
equipment that protect the wearer against airborne droplets and particles,
such as the coronavirus that causes COVID-19.

"A cloth mask or surgical mask protects others from droplets the wearer
might expel, but a respirator mask protects the wearer by filtering out
smaller particles that might carry the virus," Nguyen said.

High demand during the COVID-19 pandemic has created severe shortages
for health care providers and other essential workers, prompting a search
for creative approaches to sanitization.



========================================================================== "There are many different ways to sterilize something, but most of
them will destroy the filtration or the fit of an N95 respirator,"
Verma said. "Any sanitation method would need to decontaminate all
surfaces of the respirator, but equally important is maintaining
the filtration efficacy and the fit of the respirator to the face
of the wearer. Otherwise, it will not offer the right protection."
The researchers hypothesized that dry heat might be a method to meet
all three criteria -- decontamination, filtration and fit -- without
requiring special preparation or leaving any chemical residue. They also
wanted to find a method that would be widely accessible for people at
home. They decided to test an electric cooker, a type of device many
people have in their pantries.

They verified that one cooking cycle, which maintains the contents of the cooker at around 100 degrees Celsius or 212 Fahrenheit for 50 minutes, decontaminated the masks, inside and out, from four different classes
of virus, including a coronavirus -- and did so more effectively than ultraviolet light.

Then, they tested the filtration and fit.

"We built a chamber in my aerosol-testing lab specifically to look at
the filtration of the N95 respirators, and measured particles going
through it," Verma said. "The respirators maintained their filtration
capacity of more than 95% and kept their fit, still properly seated
on the wearer's face, even after 20 cycles of decontamination in the
electric cooker." The researchers created a video demonstrating the
method. They note that the heat must be dry heat -- no water added to
the cooker, the temperature should be maintained at 100 degrees Celsius
for 50 minutes and a small towel should cover the bottom of the cooker
to keep any part of the respirator from coming into direct contact with
the heating element. However, multiple masks can be stacked to fit inside
the cooker at the same time, Nguyen said.

The researchers see potential for the electric-cooker method to be
useful for health care workers and first responders, especially those
in smaller clinics or hospitals that do not have access to large-scale
heat sanitization equipment. In addition, it may be useful for others who
may have an N95 respirator at home -- for example, from a pre-pandemic home-improvement project -- and wish to reuse it, Nguyen said.

The Environmental Protection Agency and the U.S. Department of Agriculture supported this work.


========================================================================== Story Source: Materials provided by University_of_Illinois_at_Urbana-Champaign,_News_Bureau.

Original written by Liz Ahlberg Touchstone. Note: Content may be edited
for style and length.


========================================================================== Related Multimedia:
* YouTube_video:_Sanitizing_N95_respirator_masks_in_an_electric_multi-
cooker ========================================================================== Journal Reference:
1. Chamteut Oh, Elbashir Araud, Joseph V. Puthussery, Hezi Bai,
Gemma G.

Clark, Leyi Wang, Vishal Verma, Thanh H. Nguyen. Dry Heat as a
Decontamination Method for N95 Respirator Reuse. Environmental
Science & Technology Letters, 2020; DOI: 10.1021/acs.estlett.0c00534 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200806164654.htm

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