Researchers of Harvard Medical School, Boston have devised a way to decontaminate N95 respirators using household supplies: glass containers, mesh from produce bags, a rubber band, and a microwave.

The paper by Zulauf KE, Green AB, Nguyen Ba AN, Jagdish T, Reif D, Seeley R, Dale A, Kirby JE has been published on mBio 11:e00997-20. https://doi.org/10.1128/mBio.00997-20

In order to identify a generally accessible N95 respirator decontamination method, the autors focused efforts on microwave-generated steam decontamination. Microwaves are ubiquitous, and previous studies have demonstrated the effectiveness of microwave steam decontamination.

To date, however, studies examining microwave generated steam decontamination have employed both specific and laboratory generated materials (e.g., pipette tip boxes, modified reservoirs, commercial steam
bags, etc.) that may not be generally available or easily reproduced.

To identify a widely accessible, microwave-generated steam decontamination method, was utilized only common household
items, first examining whether contained steam was more effective than an open steam vessel.

As commercial microwave sterilization bags have previously demonstrated efficiency, the authors examined if common Ziploc bags might provide similar benefits. Although Ziploc bag-enclosed decontamination was effective, results indicated that Ziploc bags were not useful as they began to melt when exposed to more than 1 min of microwave-generated steam and posed the risk of thermal burns from contained steam, making the enclosed method less compelling.

Thus, in this paper authors demonstrate the effectiveness of a new affordable and simple method of N95 respirator decontamination, usingcommon household items and the ability to resterilize the respirator multiple times without detriment to filtration or fit provide a compelling disinfection method that should prove generally accessible to diverse settings, including outpatient practices, frontline providers, and remote clinical settings.

Not only did their microwave-steaming method decontaminate respirators after one 3-minute treatment, but the respirators’ fit and function were maintained after 20 decontamination cycles. Metal within the masks did not spark during treatment. The researchers write, “This method provides a valuable means of effective decontamination and reuse of N95 respirators by frontline providers facing urgent need.”