Do you need an N95 mask to protect yourself from Omicron? (And what you need to know if you have one)

With the Omicron variant continuing to surge into January, you may have noticed more people opting to wear an N95 mask — but those highly protective masks, usually reserved for medical settings, can be expensive and hard to come by.

Also, some experts say while N95s are highly effective when health-care workers are treating people infected with COVID-19, they aren't always recommended for the general public because their effectiveness is highly dependent on being able to create a perfect seal and wearing them consistently.

Gerald Evans, an infectious disease physician and and medical director of Infection Prevention and Control at Kingston Health Sciences Centre, explains that N95s are effective because they create a seal that reduces the respiration of 95 per cent of respiratory particles of a certain size.

But he said it's still not known whether a person in a setting like a grocery store would be likely to encounter particles with sufficient virus in them to make an N95 necessary.

"The benefit of them in general day-to-day use in most people is certainly more tenuous. It may worry people that if they're not wearing an N95, they're going to get infected" said Evans.

"My recommendation is that a medical mask is preferable to a cloth mask, but any sort of mask right now has good evidence that it reduces the transmission of COVID-19 by at least 50 per cent."

Marianne Levitsky, an industrial hygienist and adjunct professor at the University of Toronto's school of Public Health, said she recommends that people wear the best mask available to them, and that N95s are critical when going into situations where ventilation is poor and there are people they don't know.

"If I were to going to spend an hour doing a big shopping trip, I would probably wear a pretty good mask like an N95. If I were going in for five minutes maybe I would wear a less protective mask," she said.

"It is super important to find one that fits well and is comfortable so that you will wear it. It's actually not a good quality mask if you can't wear it."

B.C.'s Provincial Health Officer Dr. Bonnie Henry has also said she chooses her mask based on the setting — opting for medical masks in health-care settings and cloth masks in lower risk settings.

In November, the Public Health Agency of Canada (PHAC) updated its website to read, "in general, while non-medical masks can help prevent the spread of COVID-19, medical masks and respirators provide better protection. No matter which type of mask you choose, proper fit is a key factor in its effectiveness."

Fitting your N95

Levitsky said that in medical settings where N95s and other medical grade respirators are worn, they're fitted to a person's face using fit-testing — a process done either with a machine or manually by another professional.

The average person won't have access to this technology, but the PHAC says professional fit testing isn't necessary to use an N95 for day-to-day use.

You can ensure your mask fits as well as possible by molding it around the shape of their face and nose and pressing down around the mask's metal nose strip.

Levitsky recommends doing an at-home fit-test by blowing air into your mask. If you can feel the air you're blowing coming out of the mask, or if your glasses are fogging up, it's a sign that your mask is not creating a proper seal. Facial hair can also prevent a proper seal from being formed.

"You might find a mask uncomfortable at first but you can get used to it. If you can get it to fit well, then give it a try and see if that is something that can work for you."

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N95 or double-masking?

Evans said if an N95 isn't properly fit-tested, it won't live up to its promise of filtering out 95 per cent of particles — but even regular medical masks can provide a good degree of protection.

"A regular surgical mask has a filtration capacity of about 80 per cent, so there's only a marginal improvement of efficacy if they're not fit-tested," he said.

Levitsky said the downside of medical masks is that while they filter well, they create a poor seal, and tend to gape at the sides — a problem that can be helped by layering a well-fitting cloth mask on top. And if you choose to only wear a cloth mask, some are better than others.

"If you are wearing cloth masks, the ones that have three layers are better as long as you're given a good seal on the face," she said.

How do I care for my N95 mask?

Levitsky says N95s are not generally meant to be worn multiple times — but that advice has changed given how many people now need to wear them. She recommends that N95s be left to dry out for a week after a wear, either hung up in a safe, dry place, or stored in a paper (but not a plastic) bag.

Unlike cloth masks, N95s cannot be washed. If they get wet or dirty, they should be thrown away. And no single N95 mask should be used upwards of ten times.

Evans said it's important to remind people that wearing a high quality mask like an N95 won't single-handedly protect you from COVID-19, especially if you choose to remove it at any time.

"If you take the mask off to eat and drink with a group at a table at a restaurant — if that's the case then the N95 is doing nothing for you, but people believe it is," he said.

"That's where there starts to be a disconnect, because people want it to be a simple solution to a complex issue."