Raleigh, NC – The Centers for Disease Control and Prevention say you should wear twice as many masks.
Researchers at the University of North Carolina put that idea to the test by running trials to see how much extra protection, if any, would provide double masking. Friday morning they released their findings.
In a briefing, they shared their research on the effectiveness of masks in general, the importance of mask-fitting, and the added benefits of double masking.
Fit is the most important
“You really have to fit and make sure everything you wear is snug against your face,” said Dr. Phillip Clapp, assistant professor in the Department of Pediatrics.
According to Clapp, effectiveness can be increased by 20% simply by ensuring that a single mask is applied.
A mask that is not on allows air and aerosols to pass through any openings, reducing protection against COVID.
Double masking offers more protection
The tests showed that double masking offers better protection when the masks are applied.
“With double masking, we saw an increase of 15% [in protection], simply by a double masking procedure or surgical masking, ”said Clapp.
In addition, double masking can provide additional protection depending on how the wearer applies their masks.
For example, by placing a cloth mask on a surgical mask, the efficiency was increased about 40%. However, applying a surgical mask to a cloth mask did not provide comparable protection.
Mask frames, which provide a good tight fit, also offered additional benefits.
However, even double masking cannot be compared to wearing an N-95 mask.
But wearing two surgical masks and adding a frame or brace around the face to prevent leaks and create a snug fit achieved 97% effectiveness in one test.
Basically, extra layers provide extra protection – but it’s very important to make sure your mask fits properly, otherwise the spill will let aerosols through.
Finally, Dr. Emily Sickbert-Bennett, director of infection prevention at UNC, talks about the main form of ‘double masking’.
“The main ‘double masking’ is when you and the person you’re with both wear a mask,” she said.
So whether you decide to wear a double mask or not, one of the most effective ways to prevent the spread of COVID is simply for everyone to wear at least one mask.
Is wearing a mask or ‘double masking’ dangerous?
Some people have raised concerns about whether or not wearing a mask could lower their oxygen levels. Then could double masking have a potential downside?
Clapp and Sickbert-Bennett said they don’t believe this is a problem.
Clapp said people are concerned about breathing their own air again, which increases carbon dioxide and decreases oxygen.
However, he said those concerns are not supported by the science of how masks work.
“When you wear a mask, the air volume in this breathing space is very low. So when I breathe in, I draw air in from the outside,” he said.
That’s the whole purpose of masks, he explained. They are designed to filter particles from the outside air while you breathe air through the masks.
“So you’re taking in fresh air in addition to the small amount of air you exhaled earlier,” he said.
Sickbert-Bennett said, “Of all of our medical colleagues who have reported on this, it won’t be a problem.”
When can we stop wearing masks?
Since COVID is carried by respiratory drops, masks are essential to prevent spread.
“By consistently wearing masks for everyone, I think this is the best way to end the pandemic,” said Sickbert-Bennett.
She said when the handover slows down, the community can reassess when it’s time to hang our masks for good.
Until then, we can increase our protection by making sure our masks are on – and, if we want, by double masking.