When you need research that involves calculations and microscopes, you call a scientist. When you need research that involves bear spray, you call a U.S. Marine.
Bear spray particles are 3-6 microns in diameter, or somewhere between 10-60 times bigger than Covid-19. If a face mask can stop Covid-19, it should be able to easily stop bear spray. Two intrepid U.S. Marines put bear spray to the test. Well, one was intrepid for getting sprayed. The other did the spraying, ran away, and laughed.
This may not be the science we need, but it’s the science that we deserve right now.
Hattip: Dr. Ted Noel