Arizona's largest health system is for the first time telling employees to reuse their highly protective N95 masks in an effort to conserve a precious resource.

Phoenix-based, nonprofit Banner Health on Tuesday sent out a notice to employees of the policy change on masks, which was made in anticipation of a surge in patients ill from COVID-19, the disease caused by the new coronavirus, Chief Clinical Officer Dr. Marjorie Bessel told The Arizona Republic.

The health system, which has medical facilities in six states, has enough N95 masks on hand to last 14 days at normal capacity. But if capacity were to double, as it has in some areas hit by the COVID-19 pandemic, Banner Health would have enough of the protective masks to last seven, Bessel said.

N95 masks, sometimes known as N95 respirators, are not the same thing as loose-fitting surgical masks. N95 masks are tight-fitting and filter out at least 95% of particles in the air, including large and small particles. They are used by health care workers to reduce exposure to small particle aerosols and large droplets from patients.

All FDA-cleared N95 respirators are labeled as "single-use," disposable devices, but Bessel said the COVID-19 pandemic is a situation where the rules on N95 masks are changing at Banner as they have in other hospitals and health systems. The change was about conserving supplies while maintaining health workers' safety, she said.

"We're not the first ones to do it," Bessel said. "We understand that we are about to face unprecedented times and our health care workers' safety is at the absolute top of list. We can't do anything if we don't have them as safe and as healthy as we can possibly get them."

Banner to workers: Store mask in a paper bag

Typically a health care worker may reuse the N95 during a single shift if they are only using it for one patient. But for the most part, providers would put on an N95 to examine a patient and discard the mask after one use.

Health care workers at Banner Health who need to use an N95 will now receive a mask and a paper bag. They will be asked to use the mask when needed and then store it in a paper bag to allow it to breathe and dry out in between uses and shifts, Bessel said.

There's no specific time frame for N95 reuse in the Banner directive, but rather conditions listed when the mask will no longer be functional:

The mask is stretched and no longer sealing, elastic is loose, etc.

The mask is visibly soiled, or staying moist between uses.

The N95 can be used for multiple shifts so long as it does not become damaged or visibly soiled, the Banner memo to employees says.

"What we are talking about is extreme conservation. To be honest, none of us have ever done this before," Bessel said. "This is brand new territory. We are working out how we do preservation. We are working out the kinks. We just started doing the rollout, so it's certainly very in-process for us."

Conserving N95 masks is one of several actions Banner Health has taken to prepare for what could be a large surge of patients ill with COVID-19, which can cause severe respiratory illness. Other aggressive actions include canceling elective surgeries, and imposing a "no visitors" policy.

Avoiding a New York City scenario

As of Wednesday, there had been 1,413 positive COVID-19 cases reported in Arizona, including 29 known deaths from the disease. The statewide case tally jumped 252% from 401 in the March 25 numbers one week earlier.

Maricopa County's Health Department on Wednesday reported that of its 873 cases, 158 were hospitalized, or about 18%. Wednesday's county case total was up 248% from the prior week. On March 25, the county had 251 positive cases, with 35 hospitalized.

State health officials have said that given the current trajectory of the disease's spread in Arizona, illnesses here could peak in mid to late April, with hospitalizations peaking in May.

"If we were to quadruple our capacity, which is what New York City and Italy and other places are experiencing, it takes our days on hand for N95 masks to 3.5 days," Bessel said, explaining that "days on hand" means the length of time the current supply would last.

Personal protective equipment for health care workers is in short supply worldwide, she said, and distributors are doing their best to allocate. Typically, orders are only being filled to a level that hospitals and health systems have historically needed, not what they need now, she said.

"We don't have an ability when we quadruple to go to the manufacturers and say we need four times as much as we've asked for in the past," she said. "We've got to go to conservation methodology for PPE, which means we've got to go to reuse."

Bessel said Banner Health is working on finding creative solutions to the shortage of N95 masks and other kinds of personal protective equipment needed by health care workers.

A local distillery helped solve a shortage of hand sanitizer and Bessel said there are projects in the works for N95 masks, too. Possible ways to fill the need include 3D printing, and resterilization with, among other methods, an oven or UV light, she said.

Bessel said a Banner Health team is evaluating and exploring "every possible avenue that we can find" to keep appropriate amounts of PPE supplies in stock.

"We are taking action now to put ourselves in the best possible position to avoid what is happening in New York City, which is obviously very sad and a significant tragedy for all of us," Bessel said. "It's just heartbreaking."

As of Wednesday afternoon, there had been 1,374 reported deaths from COVID-19 in New York City.

Reach health care reporter Stephanie Innes at Stephanie.Innes@gannett.com or at 602-444-8369. Follow her on Twitter @stephanieinnes.

Support local journalism. Subscribe to azcentral.com today.