Respirator masks are best against Omicron, but are there other options?

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As the Omicron variant continues its rapid spread, medical experts are recommending the use of respirator masks, which are more effective at filtering out particles in the air.

But N95s are expensive, and not practical for everyone. CTVNews.ca explains the differences in masks and which one might be right for you.

The consensus among experts we spoke with was that it’s time to stop using single-layer or cloth masks. You don’t need to ditch these masks, but the key is to think of multi-layering, good fit, and proper filtration.

“It is important to understand what worked before does not necessarily work now,” said Dr. Peter Jüni, the scientific director of Ontario’s Science Advisory Table, in a phone interview. “This new variant is airborne and we need to provide the right protection against it.”

FILTER AND FIT

Given the high contagion level of Omicron, the virus can slip through single-layer cloth masks. According to the University of Alberta, early on in the pandemic, people preferred to wear a cloth mask in public, as wearing a medical-grade mask was seen as “diverting critical PPE from the front line.”

In an email to CTVNews.ca on Friday, Dr. Michael Curry, a clinical assistant professor with the University of British Columbia’s faculty of medicine, said that increasing the number of layers by doubling up on masks adds more protection than a single-layer mask. The layers block the droplets from getting through the multi-layered and tightly woven mask, according to Mayo Clinic.

Jüni stressed that a surgical mask under a cloth mask provides adequate protection. He said people frequently wear a cloth mask underneath a surgical mask, which is a huge mistake. He said that along with the proper filter, the proper fit of the mask is equally important and any gaps in a mask defeat the purpose of wearing one.

While the three-layered surgical mask provides the necessary filtration, it is often loose-fitted. A cloth mask on top of it ensures the fit is right and is closing out any gaps to filter the virus.

DURABILITY, RE-USE AND N95 ALTERNATIVES

For respirators such as N95 or KN95, there are things to be mindful of when reusing them.

“They should not crumple or get wet,” Jüni told CTVNews.ca. “If they do, then it is time to throw them away. However, if they have been wet through breathing and are not crumpled, then they can be left in clean and breathable spaces for at least 3 days before they are reused.”

Curry said before reusing respirators, one should always check the manufacturer’s recommendations but in general, these can be used for about five days if handled properly. Curry said both sides of the mask should not be touched before reusing. “The outside of a respirator should not be touched as the viruses get trapped on, and within the respirator fabric. So touching the outside of the respirator means potentially contaminating your hand,” he said.

He said that the inside of the respirator should be handled with a clean hand only. “If you smear virus particles on the inside of a respirator with a dirty hand you are defeating the purpose of breathing through a filter,” he added.

So, if respirators have been touched, wet, soiled, or more importantly, if the straps loosen or stretch (since these masks work largely by virtue of their tight seal) then it is time to replace them.

While some experts say that N95 can be used for up to five days, a recent study said that N95 respirators can be reused for up to 25 cycles if they have been decontaminated with a common disinfectant, vaporized hydrogen peroxide (VPH).

According to the Centers for Disease Control and Prevention (CDC), rotating N95 masks every couple of days after storing them in a breathable paper bag at the end of the day with a minimum of five days may help pathogens on it to “die-off” during storage.

However, N95s are ideally used in a health-care setting to protect health-care workers and since there has been a limited supply in the past, experts suggest using alternatives such as KN95, KF94, or surgical masks with a layer of cloth mask that work equally well for the general public.

Also, approved N95 masks are typically expensive in comparison to respirators such as KN95 and KF94, which are close to the level of filtration that the N95 provides. KF94 masks are also made out of material with an electrostatic charge and are becoming increasingly popular. An epidemiology professor at Columbia University told NPR that the KF94 is essentially the South Korean equivalent of the N95.

Jüni said the KN95 or a surgical mask along with a top layer of cloth mask provides similar protection as an N95 and is a good compromise. He said the cloth mask can be washed and reused with a surgical mask underneath.

EXTENT OF EXPOSURE

The level of exposure decides what type of mask is most suitable.

According to Curry, masks are not needed in outdoor environments where social distancing is maintained but in a crowded outdoor environment, it may be a good idea to wear a mask. He said N95 masks are not necessary outside the health-care environment or other high-risk situations.

While N95 provides the best protection, Jüni said it does not mean that everyone should use N95.

“Absolutely not,” he said. “If a mask is well-fitted with adequate filtration for the exposure then it doesn't mean that everybody needs an N95. He said, for example, a cashier, bus driver or Uber driver can get good protection by wearing a KN95, or a surgical mask with a top layer of a cloth mask.He added that three elements crucial to control the transmission of the virus are good ventilation, proper vaccination with the booster, and avoiding being indoors in a crowd.