Two professors have conducted much-needed research on face coverings that use alternative textiles to protect the public from COVID-19 and how to keep those masks virus-free.
Christopher J. Woolverton, Ph.D., professor of epidemiology in the College of Public Health, and Richard E. Ferdig, Ph.D., the Summit Professor of Learning Technologies and professor of educational technology, are working on research that tests the filtration efficiency of various types of personal protective equipment (PPE). The researchers have developed proven recommendations for drying face coverings, which are also known as face masks.
Two articles on their research were published in the scientific journal Applied Biosafety, both of which were authored by Woolverton, who in the first article (co-authored with a member of the Kent City Fire Department and the Kent city health commissioner) studied methods of using silica beads for drying N95 respirators. The research demonstrates how to dry masks of the exhaled, moist air trapped by N95 respirators when wearing masks for extended periods of time.
The research is particularly important because it’s a means of helping the public protect themselves during this pandemic.
“Having face-covering alternatives and methods to rapidly reuse them is essential in the fight against the virus,” Woolverton said.
Ferdig and Woolverton’s research transitioned from their original research, which focused on how to find replacement PPE for healthcare workers during a time when there was a shortage of PPE.
“Since that time, and with the ability to have more PPE, our research has focused more on the quality of materials being used for masks,” Ferdig said. “Our research is important because there is limited work in that area. We are one of a few studies not directly comparing commercial products but actual materials used for PPE generation.”
According to Woolverton, they have examined four different weaves of textiles and found that they have increased the ability to prevent particles from passing through them.
“None of them are as good as an N95 (mask), but they can be used by nonmedical folks who shouldn’t be using N95s anyway,” he said.
Formally known as N95 Particulate Respirators, they filter at least 95% of airborne particles and are approved by the National Institute for Occupational Safety and Health (NIOSH). The Centers for Disease Control and Prevention (CDC) does not recommend that the general public use N95s and instead reserve them for healthcare workers and other medical first responders.
Drying cloth masks after washing them is an important step in mitigating the virus. Woolverton explains how the coronavirus differs from some other viruses, which get released from their host cells by a process known as “budding.” The protein-bound virus pushes against the host cell membrane until the virus pushes hard enough to overcome the resistance, thus escaping the cell.
However, the coronavirus retains the host membrane and seals and uses it as an external protective layer for the virus. The outside of the membrane contains the binding proteins necessary for the virus to infect another host cell. If the membrane is degraded by detergents, alcohol or drying, then the remaining "naked" virus can no longer infect host cells. Thus, drying face coverings would help eliminate the infectious viruses, they conclude.
“As a microbiologist, I know, based on other virus studies, that once the textile is completely dry, the COVID virus degrades and becomes noninfectious,” Woolverton said. “Drying textiles should analogously inactivate membrane-bound viruses, and COVID is a membrane-bound virus."
Woolverton recommends using a textile that is two-ply and composed of cotton and polyester. The mask should have a pocket between the plies for the insertion of additional filtering textiles to be added during times of increased exposure to the virus (for example, while on public transportation).
When washing masks, the filtering materials should be thrown away prior to washing with new material being added afterward.
The COVID-19 virus can stay in masks when they are wet from exhaled, moist breath. Washing and drying (as with a clothes dryer) the cloth face coverings should inactivate any coronavirus that might have landed on the mask during its use.
Other recommendations for using and cleaning masks are as follows:
- Do not overwear your masks (see below on disposal).
- Wash your cloth masks daily. “We have heard multiple stories of people using them for multiple days without washing them,” Woolverton said. “This is also evidenced by the number of people hanging them on their rearview mirrors for ‘when they need to go into the store.’ Any sign of dirt, makeup, nasal or oral secretions inside the mask is a call to wash the mask.”
- For additional protection, most masks have a space for adding materials or filtering textiles.
- Additional filtering layers of fabric can be made from 50% cotton/50% polyester blends inserted into the pocket of the face masks.
- Be careful how masks fit. Not all faces are the same, and masks that are too big are not helpful.
- Disposable masks should be used for three to four hours, unless excessively contaminated, and then discarded immediately after known virus exposure.
- If you do have N95 masks, dry them using the techniques above.
- Discard N95 masks with damage, broken straps or if there is increased breathing difficulty, which can indicate clogging.
- ALWAYS wash/sanitize your hands after removing any mask or face covering designed to prevent virus transmission.
For information about Kent State’s College of Public Health, visit www.kent.edu/publichealth. For more information about Kent State’s College of Education, Health and Human Services, visit www.kent.edu/ehhs. For more information about Kent State’s College of Nursing, visit www.kent.edu/nursing.