Reuse of N95 masks grows, though experts raise safety concerns

Beaumont Health in Michigan is one of many health systems across the country that have been forced to look at ways to reuse its supply of N95 respirator masks.

It became clear in mid-March that the system’s inventory wouldn’t be enough to handle the surge of patients it was treating with COVID-19 symptoms. As of April 13, the eight-hospital system has treated more than 1,600 patients with the virus.

“As the number of cases were ramping up, we were realizing the supply of N95s was limited,” said Dr. Sam Flanders, chief quality and safety officer at Beaumont.

The combined use of ultraviolet light and heat to decontaminate N95 respirator masks came up as a viable option that Beaumont decided to pursue given the research supporting its effectiveness on many different brands of respirators. The Centers for Disease Control and Prevention also supports the method in recent guidance. Within 24 hours, Beaumont was able to transform an unused operating room at one of its hospitals into a space designed to decontaminate 1,000 masks every eight minutes.

“Our engineers got this idea and they stayed up all night and built this unit,” Flanders said.

While health systems are being forced to make these innovations, there’s concern for the safety of patients and caregivers. N95 respirator masks weren’t meant to be reused. The masks are disposable for safety reasons.

“One thing I always remind people of because it’s something that is easily forgotten is that a used N95 mask is a biohazardous waste; that is what it is,” said Dr. Larry Chu, a professor of anesthesiology, perioperative and pain medicine at Stanford Medicine who has studied methods to clean N95 masks. “When we are disinfecting it, we are processing biohazardous waste and if it’s not processed correctly, I’m putting that biohazardous waste back on my face.”

Ventilators are another vital device that has been in short supply, which is forcing providers to look for alternatives or even weighing hooking up two patients to a single ventilator, a tactic deemed incredibly risky by critical-care specialists. “I’m not going to judge people (who hook up two patients to a single ventilator) but the single fact of the matter is there is nothing as safe as” one ventilator for one patient, said Richard Branson, a respiratory therapist at University of Cincinnati College of Medicine and a member of the Society of Critical Care Medicine.

Health systems have been thrust into this position largely because of a global shortage of N95 masks. In the U.S., the Strategic National Stockpile was depleted during the 2009 H1N1 influenza pandemic when 85 million respirators were distributed. Public health experts have lamented that the reserves were never replenished. For their part, health systems are trying to be diligent about the new solutions they are trying, but this is unfamiliar terrain.

Beaumont Health for instance is only allowing masks to be reused up to three times. Evidence supports that N95s can withstand ultraviolet light for more cycles without deteriorating in functionality, Flanders said, but the system is being cautious.

Furthermore, the system has gone the extra step of ensuring all caregivers get the same mask back from cleaning.

“We weren’t comfortable giving back a mask from a different person,” Flanders said. “The fit might be different and … in the unlikely event anything was left on there, the person knows it’s theirs.”

There are still risks with using ultraviolet light, though, said Karen Hoffmann, immediate past president of the Association for Professionals in Infection Control and Epidemiology. Because ultraviolet light is a precise beam of light, it runs the risk of missing some parts of the mask because it’s not a smooth straight shape.

Beaumont has tried to combat that concern by building eight walls in the OR space that reflect the UV light, hitting all parts of the mask, as well as putting the mask through a heating process afterward just to be sure.

“The ultraviolet light should be sufficient but we decided to add the heat as an extra measure,” Flanders said.

Another method backed by evidence that it can clean N95 masks is vaporized hydrogen peroxide, which is also recommended by the CDC.

OhioHealth struck up a partnership with the research and technology company Battelle to use its vaporized hydrogen peroxide process to reuse its N95 masks.

Battelle has been researching the use of vaporized hydrogen peroxide to decontaminate N95 respirator masks since 2015 when it received funding from the U.S. Food and Drug Administration to conduct tests after the SARS outbreak.

“We know that vaporized hydrogen peroxide works for N95 because of our three years of research on N95 masks,” said Matt Vaughan, president of contract research at Battelle. In late March, the FDA approved Battelle’s process for reusing N95 masks up to 20 times. Its process has since been deployed in New York City.

OhioHealth sends its used N95 masks to Battelle’s nearby facility where they are cleaned. The 12-hospital system is relying on Battelle to ensure the masks are decontaminated, said Chris Clinton, vice president of shared services at the system.

Battelle uses a multistep process that involves inspecting the masks before and after they are soaked. Any mask with blood or makeup isn’t eligible for reuse and is disposed of. The process takes 8 to 12 hours.

While Battelle has studied the use of vaporized hydrogen peroxide on N95 masks, Chu said there are areas of concern. For one, Battelle’s research didn’t involve the novel coronavirus, known as SARS-CoV-2, but bacteria that cause anthrax.

Vaughan said while that’s true, he argues the bacteria that causes anthrax is harder to remove than SARS-CoV-2.

“This is not the hardest of viruses and if you challenge it, it’s pretty easy to kill,” he said.

Battelle also tested for proper mask fit by using mannequins, which Chu criticized.

“Quantified fit testing on humans involves moving our heads left to right, up or down; these are things that people do in real life that determine if the mask passes or fails the fit test,” he said.

Similar uncertainties are present for the use of heat or ultraviolet light. In its recent guidance on N95 reuse, the CDC admits that it doesn’t evaluate how respirator filters are impacted as part of performance requirements.

Given the uncertainty around the data, it’s a risk health systems are taking when their clinicians use decontaminated N95 masks and it should be a last-resort decision only, said Dr. Marcus Schabacker, CEO of ECRI and an intensive-care specialist.

“It’s not a good situation and it’s very worrisome that the people at the front lines are not equipped properly,” he said. “It’s like if we sent our soldiers into a fight with bayonets instead of machine guns. That’s essentially what we are doing.”

And because wearing personal protective equipment including N95 respirators routinely is new territory for caregivers, it’s especially important health systems have protocols in place to monitor how the equipment is put on and removed, a process called donning and doffing, APIC’s Hoffmann said.

Infection-control specialists in health systems should be called on to help train and oversee staff to ensure equipment is properly handled, she said.

“There is a lot of concern among infection preventionists that healthcare workers understand putting on and taking off and managing their mask correctly so they aren’t infecting themselves,” she added.

An alternative to N95 respirators is powered air purifying respirators, which are battery-operated loose-fitting helmets that provide air flow to the user. Schabacker said these respirators are preferred for safety reasons over N95 masks because they are designed to be reused and completely cover the worker’s face. It’s debatable what respirator is more comfortable.

Schabacker argues air purifying respirators are easier to wear because they are loose fitting and don’t obstruct breathing like N95 masks, which fit tightly on one’s face and after hours of use, can cause bruising.

Phil Gregg, OhioHealth’s director of safety and emergency management, said while the system is using some air-purifying respirators, clinical staff prefer the N95s because they are easier to take off and put on. The helmets of air-purifying respirators are also characterized as being heavy and bulky.

An interim final rule released by the CDC has approved the development and use of smaller, more lightweight air-purifying respirators to try to address those criticisms. The CDC is hoping the new devices will also increase the  respirator supply for healthcare workers.

Additionally, hospitals have far more N95 masks than air-purifying respirators, likely because N95s are less expensive. An assessment by the Association of State and Territorial Health Officials estimated that U.S. acute-care hospitals had no more than 83,196 powered air-purifying respirators in 2012 compared with more than 114 million N95 masks. The typical cost of an N95 mask is between 75 cents to $1.50 while the air-purifying respirators cost nearly $800 each.

Dr. Sam Flanders at Beaumont Health said while the system is interested in lighter air-purifying respirators, it will likely take some time before they are manufactured. Beaumont “will continue its current strategy of disinfection and re-use of N95 masks for now,” he said.

Once the pandemic is over, changes in emergency preparedness guidelines nationally must be explored, Schabacker said.

Flaws in the management of the Strategic National Stockpile run by the federal government became clear as states reported some supplies were expired and unusable when they received shipments. “The national stockpile needs to be re-evaluated, that’s the main thing we have learned from this,” Hoffmann said.

Ensuring the stockpile is routinely monitored going forward must occur, Schabacker said. Potentially selling supplies to providers for a discounted rate as they near expiration is also an option so the government can more readily refresh the stockpile.

In terms of ventilator shortages, Schabacker argues it’s not that hospitals should be buying more ventilators, but regions need to work together more collaboratively on sharing these devices when emergencies occur. The Trump administration in mid-April announced an initiative in which several health systems, including HCA Healthcare and CommonSpirit Health, are donating machines to hospitals in need. “We don’t have a shortage of ventilators in the U.S., we have a shortage of ventilators in New York City,” he said on April 7.