Raleigh, NC – The Center for Disease Control and Prevention says you should double the use of masks.
Researchers at the University of North Carolina put that idea to the test, conducting tests to see how much extra protection, if any, the double mask would provide. On Friday morning, they released their findings.
At a briefing, they shared their research on the effectiveness of masks in general, the importance of mask fitting and the extra benefits of the double mask.
Adjustment is the most important
“You really need to take care of the fit and make sure that whatever you are wearing is well fitted to your face,” said Dr. Phillip Clapp, assistant professor in the Department of Pediatrics.
According to Clapp, simply ensuring that a single mask is put on can increase effectiveness by 20%.
A mask that is not installed allows air and aerosols to pass through all openings, which reduces protection against COVID.
Dual masking offers greater protection
Tests indicated that double masking provides greater protection, provided the masks are put on.
“With the double mask, we saw an increase of 15% [in protection], just by double masking or surgical masks, “said Clapp.
In addition, the double mask can provide extra protection, depending on how the user applies the layers of their masks.
For example, placing a cloth mask on top of a surgical mask showed an approximately 40% increase in efficiency. However, placing a layered surgical mask over a cloth mask does not offer similar protection.
The mask frames, which help ensure a good fit, also provide extra benefits.
However, even double masking does not compare to using an N-95 mask.
But wearing two surgical masks and adding a frame or support around the face to prevent leaks and create a good fit has achieved 97% effectiveness in a test.
In short, extra layers provide extra protection – but it is very important to make sure your mask fits, otherwise the leak will allow aerosols to pass through.
Finally, Dr. Emily Sickbert-Bennett, UNC’s director of infection prevention, addressed the most important type of ‘double masking’.
“The most important ‘double-masking’ is when you and the person you’re using are wearing a mask,” she said.
So whether you decide to use a double mask or not, one of the most effective ways to prevent the spread of COVID is to simply use at least one mask by everyone.
Is wearing a mask or ‘double mask’ dangerous?
Some people have been concerned that wearing a mask may lower their oxygen levels. Could double masking, then, have a potential drawback?
Clapp and Sickbert-Bennett said they did not believe this was a concern.
Clapp said that what people are concerned about is breathing their own air again, which increases carbon dioxide and decreases oxygen.
However, he said, these concerns are not supported by the science of how masks work.
“When you are wearing a mask, the volume of air inside this breathing space is very low. So when I breathe, I am pulling in the air outside,” he said.
That is the whole purpose of the masks, he explained. They are designed to filter particles from the outside air as you breathe air through the masks.
“So, you are bringing fresh air in addition to the small amount of air you exhaled previously,” he said.
Sickbert-Bennett said: “Of all our medical colleagues who have reported this, this is not going to be a concern.”
When can we stop wearing masks?
As COVID is transmitted by respiratory droplets, masks are essential to prevent spread.
“If everyone wears masks consistently, I think this is the best way to end the pandemic,” said Sickbert-Bennett.
She said that when the transmission slows down, the community can reevaluate when it is time to hang up our masks forever.
Until then, we can increase our protection by ensuring that our masks are put on – and, if we want, by double mask.