Is it safe to clean and reuse hospital masks?
As California is launching an effort to decontaminate masks for healthcare workers, experts warn that it is a tricky process
California has also set a backup plan in motion as it still ramps up its purchase of protective gear for health care workers. It is said that masks can be cleaned and be reused again. Doctors and nurses, as well as other medical workers, use face masks which are called N95 respirators. The masks do filter out infectious droplets carrying the virus. The masks are not supposed to be reused. The centers for Disease and Prevention acknowledges that hospitals may have to consider reusing the masks due to shortages of personal protective equipment., ”as a crisis capacity strategy.” The director of the California Governor’s Office of Emergencies, Mark Ghilarducci said today that the state, in partnership with the Federal Emergency Management Agency, will be deploying new sterilization systems from Ohio-based defense contractor Battelle within the next week.
“It’s a technology that is designed to get on the ground and actually bring in a used N95 mask and do a sterilization and cleaning process that makes them basically new again,” Ghilarducci said.
According to Amy Herr, a professor of bioengineering at the University of California, Berkeley alongside David Rempel, who is a professor of medicine at the University of California, San Fransico argues that the process is not that simple. They say that there is great potential for cross-contamination when sterilized masks are returned to hospitals. The masks might not fit well enough to seal out infectious droplets if the sterilized masks don’t find their way back to their owners.
“I wouldn’t call them clean masks, I would call them maybe cleaner masks,” Herr said. “They’re not as good as new.”
The two professors are part of the team that spent weeks digging through the scientific literature to create a set of best practices for decontaminating masks, compiled on a website called N95DECON.org.
“Both of us hope that none of this ever has to be done and that enough new masks come in that no hospital has to decontaminate any masks at all,” Rempel said.
Frequently Asked Questions About N95 and Reusing of Face Mask
The Battelle system that California will be deploying uses hydrogen peroxide vapor. How does that system work?
Rempel:
”There’s very strong evidence that it both decontaminates and kills any microorganisms on the mask. And it can be used over and over again up to 20 cycles without damaging the mask’s filter, or the straps or any other part of a mask. Some of the other systems, like the moist heat, and some other processes can damage the mask itself or the straps over a shorter number of cycles, so it’s obviously dangerous if a health care worker uses one of those masks, they might be using a mask that’s not protective.”
What methods don’t work for decontaminating masks?
Rempel:
”There are other methods that people are thinking about that clearly don’t work and damage the masks — like using alcohol, or maybe storing the mask overnight for a day, or dunking the mask in peroxide, or other chlorine types of solutions. Those damage the masks and should not be used.”
Herr:
”We were thrilled when CDC guidance came out. There are a lot of consumer products that are out there, and there are even some medical products that are out there that do not provide enough UV-C light to be effective for face mask decontamination. There are specific ways that UV-C light must be applied for it to be safer and effective.”
Are there any pitfalls you can foresee with this new decontamination effort?
Herr:
”When we’re thinking about these processes, for making the masks safer — not safe, but safer — for reuse, all of the handling of the mask before and after they get to the treatment is super important.
Trying to get the masks back to the initial user because the masks conform to the shape of your face. That whole handling process is absolutely critical because of that, but also because of wanting to avoid cross contamination during the handling.”
Rempel:
”I would just say that the fit issue is an important one, that making sure that the masks aren’t deformed and they come back to the original user is a key element, and that the masks aren’t decontaminated more than 20 times. That’s the limit; if you go over 20, the mask straps can break.”
What would you want to see in terms of shipping and handling to ensure there’s no cross contamination and that the cleaner masks get back to the right people?
Rempel:
”There’s a way of labeling the mask with a person’s name and the hospital and the site that it comes from, so that’s done properly. They’re placed in a special bag. The shipping process has to be done properly, and then obviously the return process to get the right mask back to the same person in a way that doesn’t allow for contamination because you don’t want people to be sticking their hands in a bag to pull out their masks using dirty gloves, for example.”