NASA’s Glenn Research Center and University Hospitals (UH) in Cleveland have collaborated to develop new methods and technologies for decontaminating personal protective equipment (PPE) for aerospace applications and for safeguarding the health of workers caring for patients with Covid-19.

A team of researchers recently developed and tested two new approaches that could enable health care professionals to sanitise masks on-site and safely reuse them. These approaches also may be useful to the aerospace community when traditional sterilisation techniques might not be available.

“NASA strives to ensure the technology we develop for space exploration and aeronautics is broadly available to benefit the public and the nation,” said Glenn Center Director Marla Pérez-Davis, Ph.D. “If our technology can lend a hand in overcoming this crisis, we will do whatever we can to put it in the hands of those who need it.”

Results of tests on both methods – atomic oxygen and peracetic acid – are promising. The atomic oxygen decontamination method currently is being evaluated and early results are favourable.

Atomic oxygen method

Glenn Research Engineer Sharon Miller and Physicist Bruce Banks of SAIC developed a process and hardware to decontaminate masks using atomic oxygen. Pervasive in low-Earth orbit, these single oxygen atoms can remove organic materials that can’t easily be cleaned by other methods.

“On Earth, we create atomic oxygen by putting ozone (O3) in a chamber and heating it,” Miller said. “As the ozone decomposes into atomic oxygen, it can kill organisms like viruses.”

Further testing is needed to verify the method can be used to perform multiple decontamination cycles without damaging the PPE. Recent filtration tests performed at an independent testing laboratory showed N95 masks filter well and pass acceptance testing after 20 minutes of atomic oxygen treatment.

In early May, NASA provided a prototype for UH to test on N95 masks. Early results confirm the method deactivates the virus, and continued testing will determine the minimum ozone concentration and exposure time needed for disinfection.

“Ozone diffuses easily through and around objects, which makes it promising for sterilising inside an N95 mask filter or loosely stacked masks, and it could potentially sterilize without leaving a residue,” said Banks, who supports Glenn’s Environmental Effects and Coatings branch.

“The process could be scaled up to treat multiple batches of PPE or made portable for small hospitals in rural areas. No liquid chemicals would be needed, just oxygen and nitrogen gas.”