Months after mask manufacturers ramped up production of N95 masks in response to the coronavirus crisis, hospitals, clinics, and nursing homes taking care of COVID-19 patients are still facing shortages of the respirators.

And while some hospitals have been provided with fairly expensive disinfection and sterilization equipment to safely reuse the N95 masks, a great number of people still lack access to such industrial-scale processes. Luckily, a recent study shows that the respirators can be safely decontaminated for reuse with simple tools you most likely have at home.

The researchers from the Harvard Medical School tested a steam disinfection approach that uses only a microwave and a couple of other commonly available household supplies. In the study, the researchers used a rubber band to attach mesh from a produce bag to a glass container, filled the container with water, and then placed a virus-doused N95 respirator on top of the mesh.

The mask was coated in MS2 phage, a virus that is harder to kill than the new coronavirus because it has a tougher outer coating, meaning that anything that destroys it will definitely work on SARS-CoV-2.

After three minutes in a standard 1,110-watt microwave, the steam from the water had killed the virus. And even after repeating the process 20 times, there was no change in the fit or function of the mask.

Of course, reusing masks that were never designed for reuse is still less than ideal, but for the many care facilities that don’t have any other option, this newly proven decontamination technique could be a lifesaver.