But instead of what pattern, logo or slogan you display, choose your mask based on its effectiveness against the deadly coronavirus in the environment you are in.
Working closely with government agencies, industry stakeholders and ASTM International, an international technical standards organization, the standards will apply to filter efficiency, sizing and fit, cleaning and recommended period of use or reuse.
For now, here’s a breakdown of respirators and masks based on current scientific knowledge, and what experts are saying on how to best use them.
What would happen if every American wore an N95-type mask for four weeks in risky settings like being indoors?
N95 respirators come in many sizes to accommodate various face shapes. When fitted to the wearer’s face and worn properly, N95-type masks can trap 95% of particles around 0.3 microns, studies have shown. SARS CoV-2 can be as small as 0.1 micron in diameter — that’s about 4 millionths of an inch.
While it may seem that N95 filters would miss the tiny Covid particles, that’s not so. Most bits of virus exit the lungs encased inside larger respiratory droplets, typically much bigger than 0.3 microns.
“In a health care setting, there’s an advantage because there’s a degree of sophisticated training to inform people how to properly wear respirators which doesn’t exist in a public setting,” NPPTL’s Szalajda said.
The N95 mask — and its sisters and brothers — is best fitted to a person’s unique facial contours on a bare face to keep the seal tight. Then the mask must be worn properly, despite the fact that such high filtration can make breathing more difficult. N95-type masks have a much higher breathing resistance than simple surgical or fabric masks.
“I’ve seen people with a full beard wearing the N95, or they’re wearing the 95 upside down, or they just have it over their mouth and not their nose and mouth because it’s easier to breathe when you’re not covering your nose,” Szalajda said.
Note: Beware of N95 masks with exhalation valves in them, since those valves put your airflow back into the environment. Also beware of knockoff N95s being sold on the internet and at some commercial stores.
- NIOSH-approved respirators carry an approval label on or within the packaging of the respirator and on the mask itself.
- NIOSH-approved respirators will always have one of the following designations: N95, N99, N100, R95, R99, R100, P95, P99 or P100.
- You can verify the approval number on the agency’s equipment list or trusted-source page to determine if the respirator has been approved by NIOSH.
In response to the spread of new, more contagious variants of the coronavirus, some European countries are mandating the use of FFP1 and FFP2 masks — which stand for “filtering facepiece respirator.”
- Note: The “P” means the mask is strongly resistant to oil and can be used to protect against nonoily and oily aerosols. In comparison, the “N” on N95 means the mask is not resistant to oil and can’t be used in an oil droplet environment (such as drilling for oil).
An FFP1 filter has a minimum filtration efficiency of 80%, an FFP2 is 94% effective and a FFP3 is 99% effective against airborne infectious diseases.
Last week the German state of Bavaria mandated that citizens use FFP2 masks when shopping in stores and traveling on public transport. The German government then followed that lead, requiring everyone in the country to wear either FFP1 or FFP2 masks while at work, in shops or traveling on public transport.
KN95 and similar filtering facepiece respirators
“However, prior to selecting a respirator,” the 3M document said, “users should consult their local respiratory protection regulations and requirements or check with their local public health authorities for selection guidance.”
They do not “filter or block very small particles in the air that may be transmitted by coughs, sneezes, or certain medical procedures,” the FDA stressed.
“Surgical masks weren’t meant to perform the functions of the respirator,” said NPPTL’s Szalajda. “They’re not intended to be protection from inhalation particles but from contact with body fluids.”
True medical-grade masks are made of three layers of nonwoven fabric typically made from plastic. The colored top layer of fabric is made of medical-grade spunbond polypropylene, which is a resin polymer heat-bonded into a weblike structure.
Surgical masks also have small, bendable wires to help the mask stay in place, and are often tied behind the head or secured with ear ties. This design doesn’t make for a particularly great fit, especially compared to the N95, according to Szalajda.
Surgical masks are one-time use only, and if they are soiled or breathing becomes difficult, the mask should be carefully discarded and replaced, the FDA said.
Homemade cloth masks
The most common mask in use among the general public today is a fabric mask, often homemade. Effectiveness depends on the type of fabric used and the number of layers of cloth. These masks can be as little as 26% effective.
According to the CDC, “multiple layers of cloth with higher thread counts have demonstrated superior performance compared to single layers of cloth with lower thread counts, in some cases filtering nearly 50% of fine particles less than 1 micron.”
That’s good news — studies have detected SARS‐CoV‐2 in aerosols between 1 and 4 microns.
“We found that silk face coverings repelled droplets in spray tests as well as disposable single-use surgical masks,” the authors wrote, adding that silk masks “can be more breathable than other fabrics that trap humidity, and are re-useable via cleaning.”
You can also add filters to your fabric mask, according to the CDC. Some are made from polypropylene, the plastic that produces static cling; others from silver or copper, which have antimicrobial properties. Studies on the effectiveness of inserts, however, are rare, so guidance is limited.
To up their odds, people have begun layering fabric masks over surgical ones for added protection.
President Joseph R. Biden has been seen wearing two masks on numerous occasions. On Inauguration Day, Transportation Secretary nominee Pete Buttigieg and his husband, Chasten Glezman, took a selfie double-masking and inaugural poet Amanda Gorman wore a surgical mask beneath her Prada version.
It’s a behavior advocated by Joseph Allen, an associate professor at the Harvard T.H. Chan School of Public Health and the director of the school’s Healthy Buildings program.
It makes good sense to double mask, according to Dr. Anthony Fauci, now chief medical adviser to Biden.
“If you have a physical covering with one layer, you put another layer on, it just makes common sense that it likely would be more effective and that’s the reason why you see people either double masking or doing a version of an N95.” Fauci told NBC’s Savannah Guthrie.
Face shields, bandanas, gaiters, ski masks and scarves
Don’t wear scarfs or knitted ski masks as a protective measure, the CDC says. Do not wear a face shield without a mask, the agency advises, as it won’t protect against tiny airborne droplets that can float under and inside the shield. And forget bandanas and neck gaiters.
In fact, gaiter masks, also known as neck fleeces, actually increased the transmission of respiratory droplets.