KN95 masks, coronavirus and tear gas — an expert explains the limits of protection

NEW YORK, NEW YORK - MAY 29:  KN95 masks for sale at a face mask vending machine during the coronavirus pandemic on May 29, 2020 in New York City. Government guidelines encourage wearing a mask in public with strong social distancing in effect as all 50 states in the USA have begun a gradual process to slowly reopen after weeks of stay-at-home measures to slow the spread of COVID-19. (Photo by Cindy Ord/Getty Images)
KN95 masks are similar to N95 masks but data has shown that their effectiveness can be slightly below that of an N95 mask.(Photo by Cindy Ord/Getty Images)

Rep. Alexandria Ocasio-Cortez is earning praise for passing out masks to protestors to protect them from COVID-19 and tear gas last week, which she shared in an Instagram post that’s earned close to 800,000 likes. “Teargas is a chemical banned in war and has no business being used by enforcement in the United States (or anywhere),” she wrote alongside a photo of herself handing out masks on the street. “Wearing an N95 mask helps protect you from both spreading COVID-19 and exposure to tear gas more than surgical or cloth masks do.”

N95 masks have become a hot commodity ever since the COVID-19 pandemic hit. The masks, which are also called N95 respirators, filter out at least 95 percent of very small particles, according to the Centers for Disease Control and Prevention (CDC). N95 masks “are capable of filtering out all types of particles, including bacteria and viruses,” the CDC says.

N95 masks “are the gold standard for healthcare settings in which aerosol-generating procedures are being performed,” Dr. Amesh A. Adalja, senior scholar at the Johns Hopkins Center for Health Security, tells Yahoo Life.

But it’s important to note that, while she discussed the benefits of N95 masks, Ocasio-Cortez said she distributed KN95 masks. These masks are similar to N95 masks, but are regulated by the Chinese government. "The KN95 is the Chinese standard," Dr. Adalja says. KN95 masks look and fit just like an N95 mask, forming a tight seal over your nose and mouth — but data from the CDC has shown that their effectiveness can be slightly below that of an N95 mask.

And, like N95 masks, KN95 masks are also hard to find right now. Yahoo Life reached out to Ocasio-Cortez’s office about how the representative obtained the masks but did not receive a response. The CDC doesn’t have an official recommendation on KN95 masks, but The New York Times says some health care workers across the country have started using them due to N95 shortages.

N95 masks have been found to be effective at helping to protect the wearer from SARS-CoV-2, the virus that causes COVID-19. A recent study from Wake Forest Baptist Health evaluated 13 different face masks and found that N95 masks have 97 percent filtration, compared to surgical masks (62 to 65 percent) and homemade face masks (1 to 79 percent). (KN95 masks were not tested in this particular study).

An N95 or KN95 mask should help protect against exposure to tear gas, Satya Achanta, assistant professor in the Department of Anesthesiology at the Duke University School of Medicine, tells Yahoo Life. These masks are designed to filter out 95 percent of aerosolized particles up to 0.3 microns in size, he says, adding that tear gas particles are deployed in three to 10 microns. “That means these masks are efficacious in protecting the wearer from tear gas inhalation,” he says.

Still, an N95 or KN95 mask won’t fully protect you. Tear gas doesn’t just affect the lungs and cause coughing, Dr. Adalja points out. “Tear gas impacts the eyes, in addition to other mucus membranes,” he says.

Public health officials currently recommend that the general public wear cloth face masks and reserve N95 respirators and other medical-grade masks for health care workers. “Those are critical supplies that must continue to be reserved for health care workers and other medical first responders,” the CDC says online. “The recommendation is still to reserve them for health care workers,” Dr. Richard Watkins, an infectious disease physician in Akron, Ohio, and a professor of internal medicine at Northeast Ohio Medical University, tells Yahoo Life.

If you only have access to a surgical mask or cloth mask during a tear gas attack, Achanta says it may be better than nothing—but it still won’t offer the respiratory protection of an N95 or KN95 mask.

For the latest coronavirus news and updates, follow along at According to experts, people over 60 and those who are immunocompromised continue to be the most at risk. If you have questions, please reference the CDC’s and WHO’s resource guides.

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