My mask got wet during a rain or snow storm, what should I do?

A discarded face mask is shown on the floor of a foodcourt in a shopping mall in Montreal, Saturday, July 18, 2020 (Photo: The Canadian Press/Graham Hughes)

OTTAWA — With the rainy, wet fall and winter days approaching in Ottawa, what should we do if our face masks get wet?

Ottawa Public Health and health experts warn your mask will lose its effectiveness when they get wet, and you should get a new one immediately.

Face masks are mandatory in all indoor public spaces in Ottawa, and recommended in places where you can't keep two metres distance.

Ottawa Public Health recommends that if your mask becomes damp or dirty, you should exchange it for a new one if you are still in a situation where you need to wear it. Health Canada says your non-medical masks should be changed as soon as possible if it gets damp or dirty.

Speaking on Newstalk 580 CFRA's Ottawa at Work with Leslie Roberts, Toronto Infectious Disease Specialist Dr. Sumon Chakrabarti said masks lose their efficacy when it gets wet.

"If you look at the mask, especially the surgical ones or even the blue ones we're seeing with the ear loops, they work by at the microscopic level, they have a net-like lattice that traps particles, that's how the thing works to help prevent your secretions from going out and others from coming in. When that thing gets wet, it just distorts it a little bit and it decreases its efficacy," said Dr. Chakrabarti.

"That's part of the reason why, when we're in the hospital setting for example, if it gets soiled or if you sneeze, or if it gets wet for any other reason we always say to change it."

Dr. Chakrabarti says he wears three-to-four face masks a day while working in the hospital.

Roberts asked Dr. Chakrabarti if you can reuse a mask frequently during the day.

"Think about it like gym clothes, you don't wear it for the duration of the day," said Dr. Chakrabarti.

"I would say with masks, you want to have a rotation, especially the cloth ones. Have a rotation and then kind of rotate them out and wash them at the end of the day. If you're using the surgical mask, wear it for the day, get rid of it, get a new one."

With winter fast approaching, Dr. Chakrabarti said the rain and snow could cause your cloth mask to lose their effectiveness.

"If you have a mask and it gets water-logged, it does lose its efficacy. We have to be careful overall, use common sense, and I think everybody will be just fine."