Earlier this March, the Department of Health (DOH) urged the public to "double mask" or wear two face masks at a time to enhance their protection against COVID-19. As the more viral Delta strain continues to spread in the country, along with the potentially as-contagious Lambda, will double masking work and protect people from the more transmissible variants?
The United States' Center for Disease Control and Prevention (CDC) recommends wearing two face masks to reduce the number of respiratory droplets containing the virus to come through the masks. Former government COVID-19 task force adviser Dr. Tony Leachon also believes this.
"Ang problema kasi natin sa Delta variant is basically the high transmission, which is yung transmissibility is 60 to 100% so five to eight persons puwede ma-infect while sa Alpha, two to four," Leachon told PhilStar L!fe.
"So pag double mask you could at least nullify yung transmissibility rate," he said. "It's an extra layer of protection."
Meanwhile, infectious disease expert Dr. Edsel Salvana believes one face mask will do. "Face shield plus mask is pretty much the equivalent to double mask. [It] also has added eye protection," he said.
How to layer masks
Layering masks isn't as simple as wearing two surgical masks at a time. The CDC has provided guidelines on how to layer masks and the benefits it gives wearers such as improving the fit of your mask to reduce the amount of air that leaks through its edges, and improving filtration by reducing the number of respiratory droplets passing through.
When you're planning to wear two masks, wear a medical-grade mask underneath a cloth one. It's inadvisable to wear two medical procedure masks as they do not improve the fit of the other one underneath.
Meanwhile, DOH Undersecretary Rosette Vergeire doesn't recommend using cloth masks alone in view of the rising COVID-19 cases and the emergence of more transmissible variants.
"Pag medical grade, ito ay ginawa mismo para ma-filter ang organismo sa hangin. Meron siyang certain layers that can filter specific particulate sizes," she said in a recent townhall.
But those who don't have access to medical-grade or surgical masks can still opt for cloth ones. “Ngayon kung hindi talaga kaya at hindi magkakaroon ng surgical mask, cloth mask is still recommended naman. Hindi naman natin sinasabi na hindi na puwedeng gamitin," Vergeire added.
DOH-TAG member Dr. Anna Lisa Ong-Lim said you can layer two cloth masks instead. “Maigi pa rin na gumamit ng cloth mask kaysa walang mask. Pwede isipin kung talagang walang surgical mask, pwede rin double cloth mask," Ong-Lim said. She also reminded the public to wear masks properly.
Meanwhile, experts say there is no need to double mask when wearing the KN95 kind. "Mas mataas [ang protection] ng N95 kasi, so kahit ayun lang," Leachon said. The CDC also says to use only one KN95 mask at a time.
"Pero pang kinombine mo yung masks and face shield plus social distancing, each one will enhance the other kahit hindi sila perfect," he remarked.
KF94 vs N95?
One may also opt for the KF94, which are now growing in popularity. Leachon, for one, said that he has also been using KF94 masks.
“I trust its quality as it’s said to also have a good filtration system,” Leachon said.
Experts say that the KF94 (which stands for Korean Filter) is almost the same as the N95 masks. In an interview with NPR, Columbia University epidemiology professor Stephen Morse said the KF94 and N95 masks are “pretty comparable.”
Morse said that the KF94 usage is growing as it is readily available due to having more suppliers and sometimes even a bit cheaper compared to the N95.
“KF94 is actually intended for public use. In Korea they are often worn by ordinary citizens to filter out dust or pollution,” said Morse.
But for daily use, experts say that surgical masks layered with a cloth mask works just as well.