An Indian student from Harvard University has come up with an innovative method to decontaminate N95 masks as there is a supply shortage due to pandemic. Tanush Jagdish, a PhD Candidate in the Program for Systems, Synthetic and Quantitative Biology at Harvard University, used microwave-steam to decontaminate N95 mask.
Jagdish tested the decontamination procedure using MS2 virus, and not SARS-CoV-2, which infects the bacterium E. coli. He explained the decontamination process in a document shared from his Twitter handle. According to the document, one should fill a plastic container with 50ml of tap water and place a perforated plate over the container.
A single respirator should be kept on the perforated plate so that the steam can get through to it. The 1250W rated, 2450 MHz commercially available microwave oven should be kept on high for 2 minutes and then inspect respirator for visible signs of deterioration, and check fit remains adequate.
The idea is that steam generated from container is sufficient to permeate mask membranes and kill close to all 10 million viruses. Using any microwave-safe mesh should work. We used easily available plastic meshes that come with clementines and oranges. (4/8) pic.twitter.com/iVI9Mc43wj— Tanush Jagdish (@TanushJagdish) April 26, 2020
While the procedure has not been approved by the Centers for Disease Control and Prevention (CDC), the result was demonstrated on N95s in some peer-reviewed studies. In a Twitter thread, Jagdish said that the filtration efficiency of masks was measured after microwave treatment in line with the Occupational Safety and Health Administration (OSHA) guidelines.
The Harvard scholar wrote that the N95 fit and function were intact even after 20 sequential microwave-steam decontamination treatments and the metal strap on the mask did not cause any issue. However, he emphasised that vaporised hydrogen peroxide (VHP) is likely the most efficient at large-scale decontamination of all methods currently available
“But if you don't have the resources to afford or access VHP, microwave-steam is a very easy and effective alternative,” he tweeted.
(Image: Twitter / @TanushJagdish)