Researchers at Sandia National Laboratories are working with local hospitals and medical device manufacturers to increase the availability of respirator masks for health care workers.
N95 respirator masks are certified to block 95% of extremely small particles without restricting breathing. Sandia engineers are conducting tests for manufacturers to determine how new mask designs measure up to these industry standards. They are also studying disinfection methods that could enable hospitals to reuse masks, lessening the need for new ones
When respirators ran low in hospitals, Albuquerque companies Marpac, Sierra Peaks and Sew-EZ approached Sandia for help testing materials outside the typical supply chain that could be used to manufacture more. Examples included materials used for heating and air conditioning systems, as well as vacuum bags.
To help in this effort, a Sandia team modified its aerosol and filtration equipment for nuclear nonproliferation work to conduct tests and comparison studies for the mask projects.
Through these tests, researchers identified the most promising filter media, comparable to N95 filtration, to use for respirator production.
Sandia is also working with the University of New Mexico Hospital to determine how to safely decontaminate and reuse respirators. The team is assessing a hydrogen peroxide vapor method being used by UNM Hospital, as well as less-specialized techniques that could be used at smaller hospitals. The study also examines the effect of repeated decontamination cycles on N95 masks’ filtration, fit and mechanical integrity. It is cataloging how different makes and models of respirators break down under various decontamination methods.
Sandi is also exploring new decontamination methods, including supercritical carbon dioxide, a solvent that has properties of both a liquid and a gas and is becoming popular as an eco-friendly alternative for dry cleaning. Many conventional sterilization methods cannot be used because they degrade mask performance, but supercritical carbon dioxide is gentler than other chemical disinfectants and works at relatively low temperatures.
The hope is that it can safely and reliably sterilize N95 respirators and other critical medical supplies for reuse on the front lines of the COVID-19 pandemic. If it is found to be appropriate and effective, it could be rapidly deployed at hospitals nationwide because it is already used in commercial dry-cleaning.
“We’re helping local medical device manufacturers test materials they are using to make medical-grade masks, and we’re helping local hospitals by evaluating methods they’ve developed to clean N95 masks for reuse.” says Sandia researcher Gil Herrera. “We’re providing them information they need to make decisions regarding the reuse of sterilized N95 masks and alternatives to N95 masks to protect health care workers and patients.”
Assistance has been provided at no cost to partners through a combination of internal funds and funding from the Department of Energy Office of Science.