Some health officials on the White House Coronavirus Task Force said in February that masks were not effective in preventing the general public from catching the virus. As they learned more about transmission, those recommendations changed, and Americans were then urged to wear them. Now, recent studies have found that while some face coverings provide protection, others are inadequate while some could be even worse than wearing nothing at all.
The Centers for Disease Control and Prevention (CDC) guidelines indicate “masks should NOT be worn by children under the age of 2 or anyone who has trouble breathing, is unconscious, incapacitated, or otherwise unable to remove the mask without assistance.” For everyone else, wearing face masks while maintaining physical distance is recommended as the best way to slow the spread.
The CDC’s updated guidelines follow a much-quoted late-February statement by the U.S. Surgeon General, who has since walked it back.
Seriously people- STOP BUYING MASKS!
They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can’t get them to care for sick patients, it puts them and our communities at risk!
https://t.co/UxZRwxxKL9— U.S. Surgeon General (@Surgeon_General) February 29, 2020
While the CDC now recommends wearing masks in addition to following other social distancing measures, all facial coverings are not equally effective. The following is a general breakdown of the most common types based on the most recent information from those deemed to be experts on the subject.
1. N95 Respirator Mask
N95 masks are widely considered to offer the most protection. The devices are useful for preventing the wearer from both catching and spreading the virus. However, the CDC does not recommend that the general public wear them. The federal agency considers N95’s “critical supplies that must continue to be reserved for health care workers and other medical first responders.”
The N95 mask appears to be the most effective mask. pic.twitter.com/509UOrqwX1
— Abubakar Ali Abatcha (@Abubakarjarawa) August 12, 2020
The supply of N95 masks has been limited since the early stages of the pandemic. As the Wall Street Journal reported:
N95 masks filter out at least 95% of very small particles when worn properly, including droplets carrying viruses. Versions with a plastic valve at the center, which makes the mask easier to exhale through, are intended for industrial workers and offer protection only to the wearer.
True N95s aren’t easy to wear properly. They must have a tight seal to the face to ensure that all air goes through the filter instead of around the edges. But they offer the best protection against the coronavirus…
The Strategic National Stockpile was badly depleted when President @realDonaldTrump took office.
We have tripled the number of N95 masks, tripled the number of gowns, and quadrupled the number of ventilators on hand. pic.twitter.com/fZE8tTRmoG
— The White House 45 Archived (@WhiteHouse45) August 14, 2020
The outlet went on to emphasize that there are contamination risks when removing an N95 mask and indicated they could be re-used after being stored in a paper bag for at least five days.
The CDC cautions consumers about counterfeit N95 knockoffs and issued warning signs on how to spot fake versions that have not been approved by the National Institute for Occupational Safety and Health (NIOSH).
2. Fabric masks.
The CDC recommends that people who are not health care professionals “use simple cloth face coverings when in a public setting to slow the spread of the virus.”
Cloth masks are intended to prevent the wearer from transmitting COVID-19 but are not meant to protect the wearer from airborne particles like the N95.
Finally got some cloth masks. pic.twitter.com/OMubNTqGUZ
— Butts (@Viking_Lass) August 10, 2020
According to the Wall Street Journal, “a good cloth mask filters well and is comfortable to breathe through,” and “should consist of three layers: an inner layer near the mouth that can get moist, a middle filtration layer and another layer exposed to the outside environment.”
National Public Radio recently reported, “researchers say a tight-weave 100% cotton” mask tends to be a better option than those made of synthetic fibers. The outlet cited a study that recommended inserting additional protective layers inside cloth masks to increase filtration efficiency, with “the best bet” being an unwoven, breathable polypropylene material.
Some doctors advised against using a coffee filter, which they said is difficult to breathe through and effectively redirects the airflow around it.
Health experts say cloth masks should be washed after each use.
Cloth masks should be washed after each use. 😷🧼 They can either be hand washed or thrown in the washing machine with other laundry. Be sure it’s completely dry before rewearing. pic.twitter.com/iWeLVwTcmC
— Jackson County Health Department (@JacksonCountyHD) August 14, 2020
The World Health Organization rated the best materials to use for homemade masks based on breathability and filtration rating. It found polypropylene is the most effective, followed by cotton (knit), polyester (knit), then cellulose.
3. Surgical masks.
The CDC emphasizes that surgical masks are much different than cloth masks and recommends they be reserved for medical professionals, like N95.
“Masks are not surgical masks or respirators,” the CDC website differentiates.
The Wall Street Journal reported that surgical masks have “a more sophisticated design” than their cloth counterparts, allowing them to contour to the face but with a looser fit than the N95. They are made from polypropylene and primarily intended to protect others from the wearer.
Homemade masks or surgical masks?pic.twitter.com/fezSJH3MKW
— Harsh Mariwala (@hcmariwala) August 16, 2020
According to the U.S. Food and Drug Administration, “surgical masks are made in different thicknesses and with different ability to protect you from contact with liquids,” and:
If worn properly, a surgical mask is meant to help block large-particle droplets, splashes, sprays, or splatter that may contain germs (viruses and bacteria), keeping it from reaching your mouth and nose. Surgical masks may also help reduce exposure of your saliva and respiratory secretions to others.
While a surgical mask may be effective in blocking splashes and large-particle droplets, a face mask, by design, does not filter or block very small particles in the air that may be transmitted by coughs, sneezes, or certain medical procedures. Surgical masks also do not provide complete protection from germs and other contaminants because of the loose fit between the surface of the mask and your face.
A scientific adviser that helped craft the World Health Organization’s mask recommendations said the polypropylene used to make surgical masks holds a short-term electrostatic charge that can trap incoming and outgoing droplets.
Friendly reminder that surgical masks shouldn’t be reused. pic.twitter.com/qiyiwq3R9i
— Michael (@mswanson0) August 14, 2020
Surgical masks are not intended to be used more than once, and the FDA suggests placing used items in a plastic bag before discarding them in the trash.
4. Face masks with exhalation valves or vents.
The CDC recently determined that wearing some types of face masks can be counterproductive.
“Masks with exhalation valves or vents should NOT be worn to help prevent the person wearing the mask from spreading COVID-19 to others,” the agency added to its website earlier this month.
CDC Now Says Face Masks With Vents Or Valves Don’t Prevent Spread Of Coronavirus https://t.co/js2pPbVunk pic.twitter.com/Nk17mHoG8w
— Daily Wire (@realDailyWire) August 13, 2020
According to the CDC:
The purpose of masks is to keep respiratory droplets from reaching others to aid with source control. However, masks with one-way valves or vents allow air to be exhaled through a hole in the material, which can result in expelled respiratory droplets that can reach others. This type of mask does not prevent the person wearing the mask from transmitting COVID-19 to others.
5. Neck gaiters and bandanas.
Researchers from Duke University recently tested 14 types of face coverings to evaluate their effectiveness in reducing the transmission of respiratory droplets during regular speech. They concluded some cotton cloth coverings are almost as protective as standard surgical masks, but “some mask alternatives, such as neck fleece or bandanas, offer very little protection.”
Nancy Pelosi wears a bandana to Dem victory lap presser after Senate passes 4th #coronavirus bill
'Leader McConnell simply tried to steamroll us,' Chuck Schumer says. 'It's much better to talk with us than steamroll us.' pic.twitter.com/aNV23BbMQv
— Steven Nelson (@stevennelson10) April 21, 2020
The research group examined individual particles released from a person’s mouth while speaking into a box.
Warren S. Warren, a professor of physics, chemistry, radiology, and biomedical engineering at Duke, co-authored the study. He told the Washington Post the team used a laser and cell phone camera to capture images of airborne droplets passing through various coverings as test subjects spoke.
“You can really see the mask is doing something,” Warren said. “There’s a lot of controversy and people say, ‘Well, masks don’t do anything.’ Well, the answer is some don’t, but most do.”
Wearing A ‘Neck Gaiter’ May Be Worse Than No Mask At All, Study Finds https://t.co/PsiuTatevm pic.twitter.com/JxVeqVM1pG
— Daily Wire (@realDailyWire) August 11, 2020
As The Daily Wire previously reported:
The study, published (August 7) in Science Advances, found that a properly fitted N95 mask, typically worn by medical personnel, was the most effective, meaning no droplets came out at all when test subjects spoke into the box. But the neck gaiter – the one tested by the researchers was called a “fleece” and made of a polyester spandex material – ranked worse than the no-mask control group…
Duke University physics professor Martin Fischer said the gaiters changed the droplets being emitted. “We attribute this to the fleece, the textile, breaking up those big particles into many little particles,” he said. “They tend to hang around longer in the air. They get carried away easier in the air. So this might actually be counterproductive to wear such a mask. So it’s not the case that any mask is better than nothing.”
Some doctors argue that more data is needed to truly determine the usefulness of neck gaiters in preventing the spread, pointing out that researchers only tested one type that was made of a very thin fleece.
Public health officials previously advised the people to wear neck gaiters, bandanas, and homemade facial coverings to prevent supply shortages of N95 and surgical masks.
6. Face Shields.
While NFL players and teams are experimenting with face shields as a precautionary measure, public health experts advise against the general public wearing them in place of a facial covering.
Over the weekend, Ohio Republican Governor Mike DeWine announced the state “is following federal guidelines and prohibiting the use of face shields as a substitute for face coverings/masks” as public schools prepare to reopen.
As schools get ready to start the new academic year, @OHdeptofhealth is following federal guidance and prohibiting the use of face shields as a substitute for face coverings/masks.
FAQ: https://t.co/ga29kw38ex pic.twitter.com/2aYeILU6Iy
— Governor Mike DeWine (@GovMikeDeWine) August 15, 2020
According to the most recent information from the CDC:
A face shield is primarily used for eye protection for the person wearing it. At this time, it is not known what level of protection a face shield provides to people nearby from the spray of respiratory droplets from the wearer. There is currently not enough evidence to support the effectiveness of face shields for source control. Therefore, the CDC does not currently recommend use of face shields as a substitute for masks.
However, some health professionals suggest there could be benefits to wearing a face shield in conjunction with a mask.