What doctors wish patients knew about wearing N95 masks

Visto en AMA

Throughout the COVID-19 pandemic, physicians and other health professionals have continued to stress the everyday necessity and importance of wearing masks to protect against the spread of SARS-CoV-2. While reusable cloth masks have been recommended until recently, the Centers for Disease Control and Prevention (CDC) and other experts acknowledge N95, KN95 or KF94 masks provide the most protection when in public indoor spaces given how transmissible the SARS-CoV-2 Omicron variant is.

With National Institute for Occupational Safety and Health (NIOSH)-approved N95 masks no longer in short supply, CDC guidance provides that people may choose to wear a NIOSH-approved N95 mask for personal use instead of a cloth mask. N95 masks filter up to 95% of particles in the air when approved by NIOSH and proper fit can be achieved. People should be aware, though, that about 60% of KN95 masks in the United States are counterfeit and do not meet NIOSH standards.

The AMA’s What Doctors Wish Patients Knew™ series provides physicians with a platform to share what they want patients to understand about today’s health care headlines, especially throughout the COVID-19 pandemic.

In this installment, two AMA members took time to share what patients should know about wearing N95 or KN95 masks, which are types of specialized filtering masks that doctors and others in health care call respirators. They are:

• Louito Edje, MD, a family physician and associate dean of graduate medical education at the University of Cincinnati Medical Center.
• Luis Seija, MD, an internal medicine and pediatrics resident at Icahn School of Medicine at Mount Sinai in New York City. Dr. Seija is also a delegate for the AMA Resident and Fellow Section and the AMA Minority Affairs Section.

“Now, more than ever, we need to decrease the transmission of COVID-19,” said Dr. Edje, noting that “Omicron is the most contagious of the variants, so far. It is three times higher than that of the Delta variant and the second most contagious virus known to man, only second to measles.

“This is the reason that N95s are recommended for use by the general public,” she added, noting that “N95 masks offer the highest level of protection because they protect against both large and small particles rather than just large particles.”

Additionally, N95 masks “are made of multiple layers of a synthetic fiber called polypropylene and if they are worn as instructed, they block 95% of particles in the air from passing through,” said Dr. Edje.

It is also important to note that “international brands of N95s are KN95s—certified in China—and KF94s, which are certified in South Korea,” said Dr. Edje. “The KN95 and KF94 masks block 94% of particles in the air.”

But be mindful of “masks with valves that make them easier to breathe through,” she said. That’s because “they don’t filter the air the wearer breathes out and are not recommended.”

“All masks should cover the face from the bridge of the nose—where glasses would sit—to under the chin,” said Dr. Edje. “The wearer should be able to turn his or her head to either side, and up and down without the mask gaping at the edges.”

With N95s, “do not twist the loops to tighten the mask as this produces gaps and decreases the effectiveness of a mask by about 60%,” she said.