Surgical masks are for sick people, designed to catch germs leaving your body,
There's a lot of misinformation going around about how and when to use masks to prevent the spread of the new coronavirus.
The inventor of the technology inside of surgical masks and N95 respirators wants you to know this: Surgical masks are important for sick people to wear — but everyone else should think twice.
Peter Tsai created the filtration fabric inside of most surgical masks and N95 respirators and dedicated his life to perfecting them. He spent over 30 years developing new nonwoven, microfiber fabric technology. He recently retired from the Material Sciences Department of the University of Tennessee-knoxville. Tsai explained that surgical masks are designed for catching the large droplets released by sneezes, coughs and sniffles. The masks are best for catching drops that leave a sick person's body.
This means their true use is for keeping your germs to yourself.
When surgeons wear them in the operating room, they are trying to prevent germs from landing in a patient. In densely populated cities, like Hong Kong or Tokyo, surgical masks are often worn out of politeness by people with mild illnesses.
If you are healthy, masks do not do much to prevent disease, Tsai stressed. Floating sneeze droplets can still get around the sides of loose surgical masks. Unless you live in a densely populated area (and we're talking like New York or Tokyo-level dense) where there are a lot of mild cases of COVID-19, surgical masks are unlikely to keep you healthy.
And surgical masks won't help at all if they're worn improperly.
How do surgical masks work?
Tsai explained that surgical masks are made of three layers: an outer veil, a layer of nonwoven filtration fabric and an inner veil. The two veils protect the filter fabric from abrasion.
The hardworking filter fabric is made of millions of microfibers layered on top of each other. These microfibers have been permanently electrostatically charged. An electrical field ionizes the air and then forces the ions deep into the microfibers. This charge allows the material to filter out way more gunk than it otherwise would.
“With charging, one piece of this material is as efficient as layering ten pieces,” explained Tsai, “Without charging, you'd need to use ten times the material and the breathability would be ten times lower.”
What are N95 respirator masks?
N95 respirator masks can use similar filtration material as surgical masks but usually with more layers and a much tighter fit.n95 masks are supposed to fit tightly to the face and block out most particles.
Facial hair and an improper fit can expose the wearer to airborne viruses. A properly made and fit N95 will stop 95% of particles. “People say ‘N95! N95!' but they don't even know what that means,” said Tsai. Tsai explained that not all N95 respirators are made for the same purpose. Not every respirator is built to filter out disease-causing pathogens. The "N" means the mask is built to catch nonoily particles, It does not mean it will work on everything.
Don't get scammed on surgical masks
Many masks on the market have not been tested by National Institute for Occupational Safety and Health, the federal organization that works with the Centers for Disease Control and Prevention to certify respirators for health use.
Buying respirators online is a gamble because shoppers cannot confirm whether they are built to the correct standards. Sellers on Amazon may use deceptive keywords to get people to buy respirators that are not as advertised.
Wasting masks can have serious consequences
But really, N95 masks are only for working in areas where you know there will be airborne disease, like hospitals. The average person should not need one.
“My main concern about the use of (N95) masks by the general public is that they are being used incorrectly,” said Henry Spratt, an environmental microbiologist at the University of Tennessee Chattanooga.
“It's a waste of a mask,” he continued. Spratt explained that while N95 respirators are often used on construction sites for dust particles, the way that they are used in health care settings is very different. On a construction site, fit is not as important. You might be able to get away with cleaning and reusing a respirator. That's not so in a medical setting.
“For the MERS (Middle East respiratory syndrome), which is closely related to COVID-19, scientists found that that thing could survive as long as a week on surfaces,” said Spratt. COVID-19 is thought to spread mostly through direct contact with infected, symptomatic people and droplets from coughs or sneezes. While it is not yet clear how long the new coronavirus can survive on surfaces, it's still risky to reuse a respirator or mask. “The virus is contained in mucus and that will probably stick in the material of the filter,” said Spratt. “But if that's allowed to dry out, the viral particles are smaller than the filter pores and it's still potentially infectious.”
Surgical masks and N95 respirators have very specific uses and are helpful only in particular contexts. If you are not sick, or taking care of someone who is or visiting a vulnerable relative, you probably do not need a surgical mask. Only health care workers should be using medically rated N95 respirators.
If you do wear one, the mask is only a tool. It does not substitute for practical hygienic habits like proper handwashing.
“Learn proper hand hygiene and wash your hands regularly,“said Spratt.
“Oh and try not to pick your nose," he added.