COVID-19: Are Two Masks Better Than One?

Text Size:
COVID-19: Are Two Masks Better Than One?

Since almost the start of the COVID-19 pandemic in the United States, public health experts have recommended that almost everyone wear a mask in public spaces — particularly indoor spaces where it’s difficult to maintain physical distance from other people. But especially since the most protective types of masks — such as N95 masks — remain in short supply and are generally reserved for frontline workers, many people have been left to wonder how much their masks really protect against the viral infection.

To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletter!

In an attempt to make their masks more effective, some people have taken to wearing two of them at once. Prominent public figures — including football coaches and politicians — have been spotted doubling up on masks. But is this strategy really effective? Here’s what experts say about how and when to layer your masks.

Blocking respiratory droplets

While some people complain about how it feels to wear a mask, standard cloth or surgical masks don’t significantly impede most people’s ability to breathe, according to a recent article in The New York Times on double masking — and that’s a very good thing. The point of wearing a mask isn’t to block the flow of air. Instead, it’s to block respiratory droplets that would normally travel with the air that you breathe out (and, to a lesser degree, in).

The more complicated the path these respiratory droplets have to take — navigating an obstacle course of cloth fibers — the more likely they are to be blocked by your mask. While there aren’t any studies so far that specifically examine double-masking, it’s clear from existing studies on masks and COVID-19 that these cloth barriers really are effective at preventing transmission of the virus.

One study, for example — published in June 2020 in the journal Health Affairs — found that statewide mask mandates reduced the growth rate of COVID-19 cases by an average of 2.0 percentage points 21 days after they went into effect. A a result, estimates suggest that just by May 22, 2020, over 200,000 cases of COVID-19 were prevented by these mandates.

Another study, published in July 2020 in the journal JAMA, found that in the Mass General Brigham (MGB) health system in Massachusetts — the largest healthcare provider in the state — a universal masking policy covering 75,000 employees at 12 hospitals that was implemented in March 2020 significantly reduced COVID-19 infections. Before this policy was put in place, the rate of COVID-19 positive test results among employees has increased from 0% to 21.32%, with an average increase of 1.16% per day. After a transition period in which the universal masking policy was implemented to cover all employees and patients, the test positivity rate among employees fell from 14.65% to 11.46%, with an average drop of 0.49% per day.

Why airflow is important

According to experts quoted in the Times article, maintaining your ability to breathe somewhat comfortably when wearing a mask — or masks — isn’t just a question of comfort. While the goal of masking is to block the flow of respiratory droplets, it’s equally important that air itself can move through. Once airflow is significantly restricted, instead of flowing through your mask, it may flow around it at the edges — carrying respiratory droplets with it, and defeating the purpose of the mask.

To increase the effectiveness of blocking respiratory droplets, experts recommend wearing a surgical mask — which blocks these particles better than most cloth masks, but can be loose-fitting — underneath a wider cloth mask that helps the surgical mask hug your face. The cloth mask also offers some extra protection, adding to the complexity of the path respiratory droplets must travel.

So until the pandemic is over, keep in mind that for situations in which you need extra protection, two masks really are better than one — as long as you can still breathe through them.

Want to learn more about coronavirus and diabetes? Read “Coronavirus and Diabetes: A COVID-19 Update,” “Healthy Eating During Hard Times” and “COVID-19: Staying Safe at Work.”

Quinn Phillips

Quinn Phillips

Quinn Phillips on social media

A freelance health writer and editor based in Wisconsin, Phillips has a degree from Harvard University. He is a former Editorial Assistant for Diabetes Self-Management and has years of experience covering diabetes and related health conditions. Phillips writes on a variety of topics, but is especially interested in the intersection of health and public policy.

Get Diabetes-Friendly Recipes In Your Inbox

Sign up for Free

Stay Up To Date On News & Advice For Diabetes

Sign up for Free

Get On Track With Daily Lifestyle Tips

Sign up for Free

Save Your Favorites

Save This Article