The purpose of a mask is to filter the incoming and outgoing air, and capture at least 95% of any virus particles in the air.
But—there is a lot of junk out there. Masks like the one shown below don’t actually do any filtration—the air just leaks in and out along the sides.
Then there are some that look like they partially work, and may meet surgical mask standards, but this tells us nothing because surgical masks are for big droplets and they don’t filter the air effectively because they leak around the edges.
The only clear one I know of so far that maybe does it OK is this one--at least it has 99% rated filter material behind the opaque pieces. I’m testing one of these now, and I’ll let you know!
For a full discussion of masks, go to the blog for Jan. 4th. The only mask I wear for more than ten minutes is the BROAD AirPro Mask, the one with the external fan and HEPA filter.
Highlights From Past Blogs
February 16 - Ventilation Revolution
February 11 - When Will it Be "Safe?"
February 2 - Covid-19 Testing
January 27 - How Long Does Immunity Last?
January 20 - You Need a Fresh Air Meter
January 11 - Air Purifiers
January 4 - Masks That Actually Work
December 22 - Blog Intro and History
December 15 - The Double Risk of Indoor Dining
December 13 - Omicron Symptoms
December 10 - Simple Air Filtration
December 9 - Comprehensive Guide to Covid-19 Safety in Buildings
December 6 - Solution to Pollution is Dilution
November 24 - No Magic to Six Feet