Trump says N95 masks can be sterilized for reuse. Only in a pinch, experts warn.

Reviewed by Emily Henderson, B.Sc.Apr 29 2020

As COVID-19 cases continue to climb, front-line health care workers are decrying unsafe working conditions — in particular, describing inadequate access to personal protective equipment, or PPE. Many hospitals and state lawmakers blame Washington, saying the Trump administration has not done enough to make this critical protective gear available.

But at a recent press conference, President Donald Trump suggested those claims are overblown, asserting instead that hospitals have the tools they need to sanitize and reuse protective facewear.

"We're also using a sterilization process — some great equipment that will sterilize masks up to 20 times per mask. So that's like ordering 20 times more masks. And it's working very well," Trump said at the April 23 briefing.

In fact, the question of reusing masks — specifically, the highly effective N95 respirators that best protect wearers from COVID-19 - has emerged as a major worker-safety concern. Traditionally, the masks have been designated only for single use.

But with hospitals running low on protective equipment, many seek to stretch their supplies.

With that context, we were curious — can N95s be sterilized and reused, as Trump suggested? And if so, are disinfected masks as protective as new ones?

We contacted the White House but never heard back. Our own research revealed the situation is more complex than Trump suggested. Hospitals are using new technology to sterilize masks. Some procedures do show promise. Still, according to experts we consulted, it's an overstatement to suggest they are as effective as getting new equipment.

The Battelle process

Trump appears to be referencing technology from the Battelle Memorial Institute, a nonprofit technology company in Ohio. Battelle, which has an in-house "critical care decontamination system," received emergency authorization from the Food and Drug Administration to sanitize N95s for reuse.

Hospitals send used N95s to Battelle, which has also set up N95 sanitization centers in coronavirus hot spots, including New York, Boston, Seattle and Washington, D.C.

Workers wearing protective gear load the respirators into a sealed container. Masks are cleaned with vapor-phase hydrogen peroxide, aerated and then sent back to the originating hospitals. The decontamination process takes about 12 hours. A mask's round-trip journey from a hospital to Battelle in Ohio and back again can take about 10 days.

Battelle said masks can withstand the decontamination process up to 20 times without losing their ability to filter out viral particles.

So, the president is right that this technology exists. But is it fair to say the approach is the equivalent of buying new gear?

Put simply, no. Experts are clear that decontamination works in the current emergency. But - despite Trump's enthusiasm — it is not a best practice.

"It's not accurate to say that reprocessing respirators is as good as purchasing 20 of them," said Dr. Patrick Kenney, medical director of Yale-New Haven Health's supply chain, who has also researched decontamination technology and processing. "This is not a renewable resource. The respirators are intended for single use."

The reasons are multiple. For one thing, research is limited on how effective this type of decontamination is. Also, masks vary in how they stand up to the procedure.

And it's not as simple as doing a load of laundry. "Decontamination is a complicated process," said Hana El-Samad, a professor of biochemistry and biophysics at the University of California-San Francisco, who researches N95 sanitization. "Assessing how well it works and which N95 makes and models remain unaffected is an area of active research," she said.

N95Decon, a research collaborative with which El-Samad works, has examined Battelle's hydrogen peroxide approach and found the chemicals appear to eliminate COVID-19 spores without damaging the mask's filtration.

Mask integrity

Performance is only part of the equation. Another is mask structure: N95s work only when properly fitted to the face.

When workers reuse and re-wear the masks, they can lose their shape, which undermines the quality of fit and renders them less protective. For some masks, per an N95 report on hydrogen peroxide, fit quality declined substantially after just five uses. For others, it took 15 wearings to see a meaningful difference.

At Yale-New Haven, Kenney said, the hospital discards 20% to 30% of respirators that could have been refurbished before they hit the 20-reuse mark because they had sustained too much wear and tear. Battelle's 20-time reusability metric, he added, was calculated without factoring in the impact of regular hospital use.

In addition, decontamination can in some cases worsen the respirator's fit.

"If [an N95] doesn't fit well, then air will leak around the sides and it doesn't matter how good a filter it is," Kenney said.

Plus, using this technology requires hospitals to have other protocols in place. Used masks must be safely collected - since they could be COVID-contaminated and pose a biohazard — and a plan must be in place to move them to and from the sanitization facility.

"These are all complicated processes that need to be done right," El-Samad said.

She offered a key takeaway: Technology like Battelle's can help. But nothing substitutes for new N95s.

Our ruling

In describing ongoing efforts to reuse protective respirators, Trump said the United States is using "some great equipment that will sterilize masks up to 20 times per mask." That, he argued, "is like ordering 20 times more masks."

It is true that technology exists to sterilize N95s up to 20 times. But there are knowledge gaps and other shortcomings that limit how effective this process is. Government authorities and health care researchers are clear that this is a crisis measure and it is in no way as effective as "ordering 20 times more masks."

The statement is partially accurate but leaves out important details that undermine the president's point. We rate it Half True.