Q&A: How do I make a mask at home? A public health professor has advice

Regional health officials are recommending you wear a mask in public as an added layer of protection against COVID-19.

That advice echoes a recommendation by Canada's chief public health officer Dr. Theresa Tam, who has advised masks in places where physical distancing may not be possible.

A lot of people are making their own masks at home. They're using different materials and even adding coffee filters to ones that have been purchased online.

But what is the right way to make a mask?

Narveen Jandu is a professor at the School of Public Health at the University of Waterloo.

She spoke with the CBC's Craig Norris on The Morning Edition about what you should think about when making a mask at home or purchasing one online.

This interview has been edited for length and clarity.

Craig Norris: When you make a mask at home it's obviously not going to be one of the N95 masks. How effective are the ones you make at home?

Narveen Jandu: The ones that you're going to make at home are not going to be as effective as the N95 masks. The N95 masks are given that naming because they are able to filter out 95 percent of particulate matter in either direction.

But of course, we want to preserve those supplies for the frontline workers and health care workers. And at the same time we want to protect our own health and well-being and that of those around us. We also want to get this economy started and allow people to venture outwards, which we started to do this week. 

So having a homemade mask, or a cotton mask or other types of face coverings can provide some sort of a protection, and it has the ability to capture some of the respiratory droplets that would be dispersed from the person wearing the mask.

C.N: What should we be thinking about as we start to make a mask at home?

N.J: If you're going to make a mask at home, I recommend just following the guidelines on the Health Canada, Centers for Disease Control and the World Health Organization web sites.

They all consistently have the same patterning available to make a mask. They highly recommend  any cotton type of a material that you might already have at home, like an old cotton T-shirt or a bandanna.

Fold it in a few different ways, and then use either elastic bands or ties to create some loose or tie backs that you can secure behind the ears or behind the head. 

C.N: Should we avoid any materials when we're making a mask?

N.J: I would stick with the guidelines that are available. Stick with cotton. You don't want to have any adverse reactions and you don't want to be blocking off your breathing space over our mouth and nose. If you're going with a material that's too thick, for example, this could be compromising your ability to breathe in and out of the mask.

C.N: Should children wear a mask?

N.J: Not if they're less than two years old. If they are wearing masks, it should be clearly explained to them why they're wearing the mask in a language that they can understand.

At the same time we also want to make sure that the children are able to attach the masks themselves and then take it off of themselves if they need to. You don't want to put a child in a situation where they're wearing a mask they're unable to take off, and then they're unable to communicate to the adults that they want to or need to take off the mask.

C.N: Some people are adding things like coffee filters or vacuum filters to their masks. Does that make a difference?

N.J: The guideline for coffee filters is also available on the websites for Health Canada, the Centres for Disease Control and the World Health Organization. I like that recommendation because this is also something that someone might already have at home. You don't necessarily need to go out and buy something new or extra, and you don't need to order anything online. 

If you insert [a coffee filter] between the layers of fabric or insert it into the pocket of a purchased mask, certainly it's going to have added ability to capture a respiratory droplet coming off of the person that's wearing the mask.

If you've got more layers of material compared to less layers of material, more layers will capture more of the respiratory droplets.

C.N: How should we properly wear a mask?

N.J: Properly wash your hands with soap and water before handling the mask and then putting it on. You don't want to risk anything from your hands contaminating the mask area.

Ideally you're either reaching behind the ears or behind the head to secure it.  Even though you've washed your hands with the soap and water, you still don't want to be touching around the face and nose and mouth area. 

Wash your hands before you take it off. Reach behind your ears, take it off, and then ideally fold it inward and put it aside to launder for the next use.