N95 mask with valve is good for smoke, bad for COVID-19

ByAlix Martichoux and Chris Nguyen KGO logo
Friday, August 21, 2020
This mask is good for smoke, bad for COVID-19: Here's the fix
An N95 mask with a valve is good for protecting from wildfire smoke, but it isn't the best for stopping COVID-19 spread. Here's how to find the best face mask for doing both as Bay Area air quality remains dangerous.

SAN FRANCISCO (KGO) -- As multiple large wildfires rage in the Bay Area, we now need to mask up for another reason. Air quality in parts of the Bay Area was the worst in the world Wednesday, with much of the East Bay and Peninsula in the "unhealthy" and "very unhealthy" categories.

Wearing a mask to protect yourself from getting or transmitting the coronavirus has become common practice over the past several months, but now we may also need to wear masks while outside to protect our lungs from the smoky air.

But does the mask you wear for COVID-19 also work during fire season? It depends.

RELATED: Bay Area air quality worst in the world as wildfires rage in all but one county

Cloth masks and blue disposable medical masks have both been proven effective in curbing coronavirus spread when worn properly, but neither of those are the best option for filtering out smoky air.

To filter out the harmful particles from the smoke, you'll need an N95 mask, like the one shown below.


But here's where things get tricky. Many N95 masks have an exhalation valve, which makes it easier for the wearer to breathe and reduces moisture buildup inside the mask, keeping you cooler. (Like the one pictured below.)

A security guard wears a mask on the field due to wildfires during the second half of an NFL football game between the Oakland Raiders and the Los Angeles Chargers in Oakland, Calif., Sunday, Nov. 11, 2018.
FILE: A security guard wears a mask on the field due to wildfires during an NFL football game in Oakland, Calif., Sunday, Nov. 11, 2018.
AP Photo/John Hefti

That's usually a win-win situation, but because the valve allows air to escape the mask, that makes them a less-than-ideal choice for mitigating the spread of highly contagious respiratory diseases, according to the CDC.

TOTAL FIRE COVERAGE: What you need to know about fires burning in the Bay Area

If your N95 mask has one of those exhalation ports, there's a pretty simple fix: You can wear a cloth or surgical mask over the N95. That way, you still have the health benefits of wearing an N95 mask during fire season, and you minimize the risk of spreading COVID-19 to anyone around you.

The best thing you can do to protect yourself from smoky air and the coronavirus is to stay inside and at home whenever possible.

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