Major Toronto hospitals are rationing surgical masks amid the current COVID-19 pandemic, and in some cases, even urging nurses and other front-line staff to use just one mask for an entire shift, according to memos obtained by CBC News.

Provincial officials have said there are enough supplies in Ontario for health-care workers, and that more masks have been ordered and are on the way. But some front-line workers in the Greater Toronto Area say they feel their safety is increasingly at risk.

"They're treating us like we're disposable," said a veteran nurse from Markham Stouffville Hospital, who did not want to be identified for fear of retaliation from hospital management.

According to a memo sent to staff on Monday that was obtained by CBC News, Mount Sinai Hospital in Toronto is now issuing a single procedure mask to health-care workers each day. A hospital source told CBC News that a nurse would typically go through five or six of these masks over the course of a 12-hour shift.

"It is important that we conserve procedure masks for the duration of this pandemic, which will go on for some time," the memo reads. It also notes that masks must be discarded and replaced if they become soiled or contaminated.

"The main value of masking, like self-screening, is to keep the environment safe for all," the notice reads.

The province of Ontario says it has has secured 12 million sets of surgical gloves, a million N95 respirators and nearly six million more surgical masks. (Justin Tang/The Canadian Press)

Sinai Health spokesperson Barbara McCully told CBC News in an email that this move is a "short-term measure" that was put in place this week as the organization transitions to a new policy outlining mask use during the pandemic, which is "currently being finalized and will be released shortly."

In another memo obtained through a source within Unity Health Toronto, which operates St. Michael's Hospital and St. Joseph's Health Centre, management said that as of Tuesday evening, all staff would only get two masks to wear over the course of their work period.

Unity Health spokesperson Jennifer Stranges told CBC news in an email that as of this time, Unity Health's supply of protective equipment is "sufficient."

"We are being conservative and using personal protective equipment rationally to maintain a safe environment for our patients, residents, staff and physicians," she said.

Anyone who is "patient-facing" is also now required to wear a procedure mask at all times in patient areas and common spaces, the notice reads. It also says that masks should be replaced if soiled or ripped.

"We do have a limited supply of [personal protective equipment]," the memo reads. "Unless we all work together and use [it] appropriately, we will have shortages."

'We are in a war'

COVID-19 is thought to spread mainly between people through respiratory droplets produced when an infected person coughs or sneezes. N95 respirators are believed to provide increased protection compared to surgical masks.

The Registered Nurses' Association of Ontario has called on the provincial and federal governments to supply front-line health-care workers with more personal protective equipment, including masks, and is warning there's already a shortage at hospitals across the province.

"The evidence of asymptomatic infection of COVID-19 necessitates that all health-care workers facing patients, residents and clients wear a surgical mask at all times," the organization said in a news release on Wednesday.

"We are in a war and the enemy is the COVID-19 virus."

The province has repeatedly said it's working hard to ensure health-care workers have the protection they need. As of Tuesday, the government said it had secured 12 million sets of surgical gloves, a million N95 respirators and nearly six million more surgical masks.

The provincial government is also looking at deploying a stockpile of some 55 million expired N95 masks that it stockpiled after the SARS crisis in 2003.

Ministry of Health spokesperson Hayley Chazan said that the federal government has also promised to provide Ontario with another 500,000 N95 respirators and one million masks.

"We expect these supplies to be delivered at various times over the coming days and weeks," she said in an email.

'Canaries in the coal mine'

Vicki McKenna, president of the Ontario Nurses Association, said guidelines concerning N95 masks have been loosened by many hospitals.

"I started to get calls from nurses [Tuesday] saying we had N95 masks for those of us working with COVID patients or those we were screening or people who were presumed, but now we don't," she told CBC News.

Markham Stouffville Hospital spokesperson Rebecca MacKenzie said in an email to CBC News that there are a "limited number of N95 masks available globally.

"Using N95 masks in settings where they are not necessary could create a supply shortage that would put staff and physicians involved in aerosol generating procedures on COVID-19 patients at great risk," she said.

But McKenna says care facilities should listen more closely to nurses on the front lines of the COVID-19 battle.

"They are the canaries in the coal mine," she said.