KN95 Disposable 5-layer Face Mask, 20-pack - $64.99

Are these even worth 65+3 bucks? Guarantee to protect me from COVID-19?

Mr. Robo wrote: ↑ Are these even worth 65+3 bucks? Guarantee to protect me from COVID-19?

https://pubs.acs.org/doi/10.1021/acsnano.0c03597

These are researchers from the Department of Materials Science and Engineering, Stanford University, Stanford, and Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, Menlo Park, California, United States.

Heating at 85*C, 30% humidity for 20 mins allows them to be re-used many multiple times. Donning/doffing the masks can also reduce efficiency over time. Presumably N95 masks have a better fit than surgical masks, too, so fiddling around with the mask will also disrupt the barrier over time. But apparently, lowering the humidity (eg. in an oven) also does not affect the efficiency, which they tested at 20 cycles.

https://pubs.acs.org/doi/10.1021/acsnano.0c03597

This research was funded by the NIH.

This study found significant degradation after just two cycles of heat treatment, however.

Overall, it seems that N95 is better if you intend to re-use them by sanitizing with dry heat. I'd say this is potentially worth it if you re-use each mask at least 6 times. The studies likely have methodological differences but perhaps if you average it out and throw each one out after at most 10 dry heat cycles, you'd be way more efficient than buying any of the disposable masks I've seen sold at Costco or elsewhere.