How effective is your face mask? Try the candle test

This very easy test can tell you a whole lot about the face covering you're wearing.

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/ Source: TODAY
By Drew Weisholtz

Cloth mask? Disposable mask? Gaiter? With so many different kinds of face coverings available, it may seem overwhelming to figure out which one will provide the best protection against the coronavirus. This test may help determine which type of mask or covering is the right choice.

“Scientists say you can check to see how effective your mask or face covering is with a simple trick,” NBC investigative and consumer correspondent Vicky Nguyen said Thursday on TODAY. “Just light a candle and see if you can blow it out while wearing a face covering.”

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Nguyen then tried the trick herself and could not blow out a candle with a two-layered cloth mask or the disposable one.

She tried a gaiter with a single layer of material and easily blew out the candle, while holding it the same distance she held it while wearing the other masks.

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When she doubled up the gaiter’s fabric, she was still able to blow out the candle.

Dr. Amesh A. Adalja, a senior scholar at the Johns Hopkins Center for Health Security in Baltimore and an infectious disease physician, sees the value in the test.

"It has biological plausibility. It is one way to measure permeability," he told TODAY. "It’s not iron-clad, it’s not the same thing as working in a cough simulator in a lab, but it is one indication of the permeability of the mask you’re wearing to the air that’s expelled from your breath and from your nose.”

The Centers for Disease Control and Prevention recommends people wear masks to prevent transmission of the coronavirus.

“Cloth face coverings are one of the most powerful weapons we have to slow and stop the spread of the virus — particularly when used universally within a community setting,” Dr. Robert Redfield, the director of the CDC, said in a statement last month. “All Americans have a responsibility to protect themselves, their families and their communities.”

The candle test also appears to support a recent Duke University study which found that gaiters may not have any positive impact against COVID-19.

"It’s not the case that any mask is better than nothing. There are some masks that actually hurt rather than do good," said Martin Fischer, Ph.D., an associate research professor in the departments of chemistry and physics at Duke told TODAY. He also noted gaiters could actually be "counterproductive" because there were more particles in the air after speaking through the gaiter than after not wearing a mask.

Adalja, who does not advocate wearing a gaiter, also said some people don't pay attention to how good masks are.

“Not all masks are equal and many people are wearing masks to check a box, not really thinking about their effectiveness,” he said.