New Brunswick

Doctor from New Brunswick develops safer, reusable N99 mask

Dr. Rene Caissie helped develop the N99 mask already being used in Ontario and Quebec

Posted: January 13, 2021

The respirator shown here was developed by Dormi Filtration, the company co-founded by New Brunswick native Dr. Rene Caissie. It's a N-99 mask, meaning it has 99 per cent filtration efficiency and is reusable up to 20 times. (Dorma Filtration/submitted)

A New Brunswick native, Dr. Rene Caissie, originally from Saint Louis de Kent, helped develop the N-99 Dorma mask now being used in Ontario and just cleared for use in Quebec.

The mask is reusable and able to filter more aerosols out of the air than the N-95 masks, currently considered the gold standard in protecting health-care workers from infectious diseases like COVID-19.

Caissie is a co-founder of Dorma Filtration, and he started working on the mask design about six months ago with the National Research Council of Canada. The work was sponsored by the Quebec government.


"The goal from the beginning was making it an N99 mask," said Caissie.

"99 means 99 per cent filtration of the particles that we want to filter, like COVID or aerosols that could transport COVID."

(Tori Weldon/CBC)

Caissie said the second part of the design was that it needed to be reusable.

"I'm a surgeon, I go into the OR, I put on a mask. When I come out of the OR I throw it away," he said.

"In the past 12 years of practicing surgery, I've thrown out thousands upon thousands of masks."


But, this mask can be sterilized in an autoclave, a piece of equipment found in most medical settings. 

"You throw it in there, you let it dry then its reusable without losing filtration efficiency."

(Dorma Filtration/submitted)

Caissie said that cost per use of the N99 is cheaper, but, "you have to change the way you do things."

It's recommended the mask can be reused 20 times before it needs to be replaced.

"Hospitals are used to giving out masks they're throwing out [afterwards], so it's kind of an easy procedure compared to taking them back and bringing them and sterilizing them."


It's not the first piece of personal protective equipment Caissie has developed. 

"I wanted to find ways to help myself and my colleagues, my hospital, so I started working on this hood, this protective hood, and that we actually got approved by Health Canada and produced it and sold it."

He's not involved with that product anymore, and now dedicates himself full-time to the N99 mask, and the team of 70 people who are involved with its production.

"We have 40 full time employees, we have day and night shift, we can produce twenty four hours a day, seven days a week."

The filters are made in Chicoutimi and the masks are put together by a company in Sherbrooke.

Caissie said the mask was cleared for use by Health Canada about six weeks ago. They are being being distributed in Quebec hospitals with a "few" contracts in Ontario, "and hopefully soon in the Maritimes," said Caissie.


Tori Weldon

Tori Weldon is a reporter based in Moncton. She's been working for the CBC since 2008.