Cloth Face Masks Won't Protect From Wildfire Smoke, Says CDC

Wildfires continue to rage across Northern California, where 1.2 million acres of land have burned in just a week. The resulting smoke is pushing air quality levels to unhealthy or hazardous across the state, according to U.S. Air Quality Index AirNow.

While a face mask can help protect you from this smoke, the cloth masks many people have been wearing as a precaution against COVID-19 probably won't get the job done, according to the Centers for Disease Control and Prevention (CDC).

"Cloth masks that are used to slow the spread of COVID-19 by blocking respiratory droplets offer little protection against wildfire smoke," the CDC states on a new section of its website dedicated to wildfires and COVID-19. "They do not catch small, harmful particles in smoke that can harm your health."

While respirator-style masks are the most protective against smoke, there are other ways to protect yourself if you don't have one.

The Best Face Masks to Protect Against Wildfire Smoke

The CDC specifically says that N95 respirators provide protection from wildfire smoke, but adds that “they might be in short supply as frontline healthcare workers use them during the pandemic.” The CDC has been encouraging people to reserve N95s for emergency responders since April.

N95 respirators are considered the gold standard in face masks. An N95 mask is a respiratory device that’s designed to fit close to the face and filter out up to 95% of airborne particles, including large and small particles.

“An N95 mask, if it’s fitted properly so that there are no leaks, works well to keep small particles out,” Raymond Casciari, MD, a pulmonologist at St. Joseph Hospital in Orange, California, tells Verywell. “Firefighters try to wear those, but they’re very uncomfortable and hot. It’s hard to breathe with an N95, but they do work.”

A P100 respirator, which filters at least 99.97% of airborne particles, can also help, Jonathan Parsons, MD, a pulmonologist at the Ohio State University Wexner Medical Center, tells Verywell. Still, neither of these masks are perfect.

“N95 or P100 masks worn correctly may provide some protection by filtering out fine particles in the smoke, but even these masks do not help with hazardous gases in the smoke,” Parsons says.

Can Other Face Masks Help?

Unfortunately, not as well as an N95 mask or P100 respirator, Parsons says. Cloth face masks “are designed to restrict the spread of infections, and not for protection from inhaling smoke,” he says.  

That doesn’t mean a cloth face mask is useless if you’re exposed to wildfire smoke, though.

“It’s probably better than nothing,” Daniel Dea, MD, pulmonary critical care physician at Providence St. Joseph Medical Center in Burbank, California, tells Verywell. “It may help keep larger particles out but the microscopic particulates—only an N95 will keep those out."

A surgical mask, if you have access to one, may be better than a cloth face mask, Cascari says. “Usually, they fit well over the nose and under the eyes and have fewer gaps,” he says.

Why Smoke Protection Matters

Wildfire smoke can be harmful to the lungs under any conditions, but it’s especially concerning in the context of the COVID-19 pandemic.

“Smoke can irritate your lungs, cause inflammation, affect your immune system, and make you more prone to lung infections, including SARS-CoV-2, the virus that cause COVID-19,” the CDC says.

Other Ways to Protect Yourself

If there is wildfire smoke in your area, and you’re far enough away from the fire to be protected without evacuating, experts say there are a few things you can do to stay safe.

• Stay indoors as much as possible. “Do everything you can to get away from smoke,” Casciari says. When you’re inside, close your windows and turn on your air conditioning.
• Pay attention to how your eyes feel. If you feel like you’re breathing OK, but your eyes are burning, Casciari says that’s a sign you need to head indoors. The tissue in your eyes similar to the tissue in your lungs and, if your eyes are impacted, part of your lungs likely are, too, he says.
• Use recycled air in your car. If you need to drive, Casciari recommends using the recycled air mode, which doesn’t take in air from outside your vehicle.