different types of face masks, and who should wear them during the coronavirus

Don't buy masks. Wear a mask if you're sick. Don't wear a mask if you're healthy. Wear a homemade mask if you're going out in public.

Advice on who should wear masks, and when and where people should put them on has erupted into a cacophony of confusing — and at times conflicting — advice in recent weeks as the novel coronavirus spreads across the US.

Scientists are also still hotly debating the most effective ways for the general public to use masks right now.

The truth is that different masks are appropriate for different people to wear at different times, and in different settings.

First, health experts stress that sick people who wear masks can help limit the spread of their virus to others. Some people don't know when they are sick, and may be unknowingly spreading infection to others when they're out and about. Home caregivers of COVID-19 patients who cannot wear a mask should also put one on.

Second, health care workers who are coming in contact with sick patients and their virus particles all day long can also benefit from some protection.

Not all masks are created equal, though: Face masks like the N95 help keep health workers safe from contracting the virus through particles released by mucus and cough sputum when they are around infected individuals.

More expensive full-face respirators should be reserved for people who have trouble breathing in regular masks, or healthcare workers whose facial hair prevents an N95 mask from sealing correctly.
Remember, you're only protected if you wear your mask correctly, so make sure it fits snugly and take it off carefully. Always avoid contact with your eyes, nose and mouth while taking a mask off. Wash your hands immediately afterwards.

The "N" in an N95 stands for "not resistant to oil" and the 95 means that during "worst case" testing, the filter was able to capture 95% of the most penetrating particles in the air (down to 0.3 microns).

A "P" mask is, by contrast, "oil proof," but that's kind of overkill for a virus that is most often transmitted through coughing and close contact between people. P100 masks filter out at least 99.97% of airborne particles, while paper surgical masks don't guarantee anywhere near the same level of protection as N95s or P100s because of their loose-fitting design.

"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," the US Food and Drug Administration says on its website.

Mask maker 3M, likewise, warns that "no matter how well a respirator seals to the face and how efficient the filter media is ... no respirator will eliminate exposures entirely."


Most people don't know how to properly wear a mask. One study conducted in New Orleans after Hurricane Katrina found that less than one in four N95 wearers (24%) were using their mask correctly.

"Common mistakes included the (metal) clip not being pressed or tightened against the contours of the user's face, straps incorrectly placed, and putting the respirator on upside down," according to the Centers for Disease Control and Prevention.

Washing your hands, staying a safe distance away from sick people (at least six feet between you and them), and avoiding touching your face when your hands are dirty are still some of the most effective measures for the general public to adopt to avoid contracting COVID-19, a disease which is spread chiefly through respiratory droplets when they are coughed, exhaled, and spit out of infected individuals.