IOM panel: Don't reuse N95 masks in pandemic

If there's no choice, then double-mask

Masks and respirators cannot safely be reused during an influenza pandemic — but if there is no choice, cover them with another mask or face shield, an Institute of Medicine (IOM) panel advises.

That is a paradox hospitals may face when supplies are limited and the need for protection is great. Manufacturers caution against the reuse of a disposable product, and the IOM experts found no scientific basis for allowing the reuse. But ultimately, the reuse of masks or N95-filtering facepiece respirators would be better than a makeshift cloth face covering or nothing at all, the panel concluded.

"It was almost an inherent Catch-22," says Donald Burke, MD, professor of international health and epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore and co-chair of the IOM committee. "Are there ways to reuse disposable masks? The answer is maybe; but a smarter way to do it is to design them and market them as not disposable."

A possibly dire scenario forms the subtext of that question. If pandemic influenza strikes worldwide, then the supply of masks and respirators will soon be exhausted and manufacture and distribution will be unlikely to keep up with the sudden demand. Health care workers and first responders won't be the only ones using the masks. Everyone from law enforcement officers to school teachers and transportation workers will want the protection.

In fact, the U.S. economy could be crippled by worker absenteeism, disruptions in transportation, and the closing of businesses and schools, according to the Implementation Plan of the National Strategy for Pandemic Influenza.

"There is a sense of urgency," says Burke, noting that the committee was given only four months to research the question of reusing masks and offer guidance.

Science is silent

Despite all the attention on influenza, there is still a dearth of scientific data, and that hampered the IOM panel's efforts.

"We really don't know for even regular seasonal flu what proportion of flu is transmitted by direct contact, [such as contaminated hands], what proportion is droplet, which would be prevented by a mask, and what proportion is aerosol," says Burke. "I know experts who will have passionate opinions about one route vs. another route. Until those scientific questions are answered for even seasonal flu, I do think we're operating in a difficult scientific vacuum."

Moreover, no one knows how a mask might be affected by decontamination efforts, such as microwaving or bleach, he says. "Even though it looked like it was intact, it would still require reasonably rigorous testing to know that the filtration properties hadn't really changed," he says.

Health care workers routinely reuse N95 filtering facepiece respirators with different TB patient encounters, but TB is not spread by contact. During the severe acute respiratory syndrome epidemic, health care workers sometimes covered their N95s with a mask or face shield to protect the surface and extend their use, Burke says.

Although the IOM panel declined to endorse the reuse of masks or disposable respirators, they suggested double-masking as an option in a worst-case scenario. "We didn't want to shirk our responsibility to at least give some guidance based on expert opinion about what might be done," he says.

The IOM panel recommended stockpiling masks and respirators and investing in reusable models, such as elastomeric or powered air-purifying respirators (PAPRs).

"[W]e emphasize that reuse should be considered an option only in circumstances in which adequate supplies simply cannot be obtained," the report states. "[W]ithout manufacturing modifications, current disposable N95 respirators cannot be effectively cleaned or disinfected and should therefore be discarded after a single use."

According to the IOM, if a health care worker must reuse a disposable respirator, he or she should:

• Protect the respirator from external surface contamination when there is a high risk of exposure to influenza (i.e., by placing a medical mask or cleanable face shield over the respirator so as to prevent surface contamination but not compromise the device's fit).

• Use and store the respirator in such a way that the physical integrity and efficacy of the respirator will not be compromised.

• Practice appropriate hand hygiene before and after removal and, if necessary and possible, appropriately disinfect the object used to shield it.

Hospitals need more guidance as they develop their pandemic influenza plans, says Shannon Oriola, RN, CIC, COHN, lead infection control practitioner in the department of infection prevention and clinical epidemiology at Sharp Metropolitan Medical Campus and chair of the National Public Policy Committee for the Association for Professionals in Infection Control and Epidemiology.

"I think they're taking a conservative approach to say, 'We don't know; research is needed.'"

For example, it would be difficult and uncomfortable for health care workers to breathe through a double mask, she notes. But if masks are sufficient protection against pandemic influenza, then hospitals will have fewer supply problems, she says. The Centers for Disease Control and Prevention has recommended contact and droplet precautions (the use of masks) for both seasonal and pandemic influenza, but further guidance is expected.

Meanwhile, says Oriola, "I think each facility at their own individual planning level is trying to beef up their supply of masks."