One 50-minute, 212 F cooking cycle in a dry electrical multicooker decontaminates an N95 respirator without chemicals and without jeopardizing the filtering or fit. Credit: Chamteut Oh
” We developed a chamber in my aerosol-testing laboratory particularly to look at the purification of the N95 respirators, and determined particles going through it,” Verma said. “The respirators kept their filtration capacity of more than 95% and kept their fit, still appropriately seated on the users face, even after 20 cycles of decontamination in the electric cooker.”
The University of Illinois, Urbana-Champaign study discovered that 50 minutes of dry heat in an electrical cooker, such as a rice cooker or Instant Pot, decontaminated N95 respirators inside and out while maintaining their purification and fit. This could make it possible for users to safely reuse limited materials of the respirators, originally planned to be one-time-use products.
Reference: “Dry Heat as a Decontamination Method for N95 Respirator Reuse” by Chamteut Oh, Elbashir Araud, Joseph V. Puthussery, Hezi Bai, Gemma G. Clark, Leyi Wang, Vishal Verma and Thanh H. Nguyen, 15 July 2020, Environmental Science & & Technology Letters.DOI: 10.1021/ acs.estlett.0 c00534.
A towel keeps the respirator from touching the heating element on the bottom of the cooker. Credit: Chamteut Oh
The scientists assumed that dry heat might be a method to fulfill all three requirements– decontamination, purification and fit– without needing special preparation or leaving any chemical residue. They also desired to find a technique that would be commonly accessible for people in your home. They decided to test an electrical cooker, a type of device many individuals have in their kitchens.
The researchers produced a video (embedded below) showing the technique. They note that the heat needs to be dry heat– no water contributed to the cooker, the temperature level must be maintained at 100 degrees Celsius for 50 minutes and a little towel need to cover the bottom of the cooker to keep any part of the respirator from entering direct contact with the heating element. However, multiple masks can be stacked to fit inside the cooker at the very same time, Nguyen stated.
The Environmental Protection Agency and the U.S. Department of Agriculture supported this work.
Professor Helen Nguyen. Credit: L. Brian Stauffer
High need throughout the COVID-19 pandemic has produced extreme lacks for health care providers and other important employees, triggering a look for imaginative approaches to sanitization.
” There are lots of different ways to sanitize something, but many of them will damage the filtering or the fit of an N95 respirator,” Verma said. “Any sanitation approach would need to decontaminate all surfaces of the respirator, but equally crucial is keeping the filtration effectiveness and the fit of the respirator to the face of the user. The researchers assumed that dry heat may be a method to meet all 3 requirements– purification, decontamination and fit– without needing special preparation or leaving any chemical residue. They note that the heat needs to be dry heat– no water included to the cooker, the temperature ought to be maintained at 100 degrees Celsius for 50 minutes and a little towel need to cover the bottom of the cooker to keep any part of the respirator from coming into direct contact with the heating element. Multiple masks can be stacked to fit inside the cooker at the same time, Nguyen stated.
They confirmed that one cooking cycle, which keeps 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 infection, including a coronavirus– and did so better than ultraviolet light. Then, they tested the filtration and fit.
Owners of electric multicookers may have the ability to include another use to its list of functions, a new research study suggests: sanitization of N95 respirator masks.
Led by ecological and civil engineering teachers Thanh “Helen” Nguyen and Vishal Verma, the scientists released their findings in the journal Environmental Science and Technology Letters.
” A cloth mask or surgical mask safeguards others from droplets the user may expel, but a respirator mask protects the wearer by filtering out smaller sized particles that might bring the infection,” Nguyen said.
” There are numerous various ways to decontaminate something, however most of them will damage the filtration or the fit of an N95 respirator,” Verma stated. “Any sanitation method would require to decontaminate all surface areas of the respirator, however equally essential is preserving the filtration effectiveness and the fit of the respirator to the face of the user. Otherwise, it will not use the best defense.”
The researchers see prospective for the electric-cooker method to be helpful for health care employees and first responders, specifically those in smaller centers or health centers that do not have access to massive heat sanitization equipment. In addition, it may be beneficial for others who might have an N95 respirator in the house– for instance, from a pre-pandemic home-improvement job– and wish to reuse it, Nguyen stated.
N95 respirator masks are the gold standard of personal protective equipment that protect the user versus air-borne droplets and particles, such as the coronavirus that triggers COVID-19.