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One essential back-to-school item for kids this fall is a face mask — the Centers for Disease Control and Prevention (CDC) and the American Academy of Pediatrics both recommend them — but finding one that’s actually protective for a child is not a straightforward task, as many parents can attest.
There’s little in the way of official guidance or research to inform evidence-based recommendations on what type of face masks works best for kids.
Search for children’s face masks on Amazon and you’ll run into a smorgasbord of options: masks with three, four, or five layers, different designs, and different materials. There’s one company selling a mask it calls an m95 model, a term the company devised.
It’s almost impossible to verify many of the claims being made by the manufacturers, or to know if they will fit your child’s face until you order some, which can get expensive.
But it’s worth looking for a good mask. A large study of more than 1 million people being conducted online by Facebook and Carnegie Mellon University found that students who wore face masks in school had a reduced risk for testing positive for the virus and getting sick with COVID symptoms. The study was published in June in the journal Science.
Delta More Contagious
The Delta variant of the new coronavirus is much more contagious than previous versions of the virus. Studies have shown that infected people carry 1000 times more virus in their nose and throat than with the viruses that circulated last winter and spring. They shed more viral particles into the air when they talk or yell or sing, making this COVID-19 causing virus much more transmissible that in the past.
What that means says Kimberly Prather, PhD, an aerosol scientist and distinguished professor at the Scripps Institution of Oceanography in La Jolla, California, is that if it once took about 15 minutes of proximity to an infected person to catch the infection, that window of risk is now much shorter.
“If you believe the 15-minute magical number, now if you take 1000 times the viral load, basically in 1 second you could inhale that same amount of virus. So it’s gone from 15 minutes to 1 second,” Prather said in an online seminar on school safety she helped to organize.
A Better Mask
What that means, is that we need to upgrade our face masks, switching away from ill-fitting fabric masks, which can offer varying degrees of protection depending on the number of layers and type of fabric that’s used, to more highly protective surgical masks or better yet, n95 respirators, which provide the highest level of filtration.
"Booster shots" that don't go in your arm:
1⃣ upgrade your mask
2⃣ add a portable HEPA air cleaner to your space
3⃣ open the windows, even just a few inches helps a lot
4⃣ run HVAC with more outdoor air and less recirculated air https://t.co/1ZmzSRaOLA
— Linsey Marr (@linseymarr) August 19, 2021
That’s harder to do for kids, who have much smaller faces.
Any masks that gapes around the edges isn’t going to work well, no matter how well it filters.
“N95s are not made to fit kids. They do not come in kid sizes, so I do not recommend N95s for kids,” said Linsey Marr, an environmental engineer at Virginia Tech, who tests face masks in her lab.
Marr says parents need to consider the attributes masks in this order of priority:
Comfort: “If your kid won’t wear it, it’s not helping at all,” she said.
Fit: “Leaks around the sides are like having a hole in your mask and aerosols carrying the virus can get right through,” Marr said.
Filtration: How well the mask blocks small particles
One option to improve fit is to layer a fabric mask over a surgical mask. The fabric mask helps to hold the edges of the surgical mask more tightly to a person’s face. The surgical mask creates better filtration.
Marr said KN94 or KN95 masks, which are being manufactured in China and Korea, are good choices. They offer nearly the same degree of filtration as an N95, and they fit closely to the face, to minimize leaks.
Check for Counterfeits
The KN94 and KN95 masks for children are widely available, but Marr said parents do need to watch out for counterfeits, which don’t perform as well.
The National Institute for Occupational Safety and Health gives examples of counterfeit products here.
There’s also a type of cloth mask that has a built-in, edge-to-edge filter layer that are made for kids.
“Some of these filter out more than 99 percent of particles and those can be very effective, if they fit well,” Marr said.
Marr has compiled and publicly posted a list of her recommendations for masks for children.
There’s also a new standard for face masks. It’s called ASTM F3502-21, and it’s published by an international organization that sets voluntary standards for thousands of products. In order to claim that a mask meets this standard, a manufacturer has to have their mask tested and demonstrate that it provides a certain level of filtration and breathability.
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