Which mask works best on your face? I was fortunate enough to visit a lab to do a super fancy fit test, but very few of us have access to this $10,000 machine. So what should normal folks do?
While visiting the 3M lab, I learned about what I’m calling the poor man’s fit test. It’s not as accurate as a real fit test, but it will help you identify big leaks. It’s pretty simple:
- Put on the mask. Make sure the metal is bent tightly around your nose.
- If the mask has two straps, make sure one strap is below your ears and one above like this:
- Lightly hold the mask in place and inhale sharply. While inhaling, pay attention to see if you feel a sensation of air or coolness around the edge of the mask. Pay particular attention to the area around the nose.
- If you feel air leaking, adjust the mask and try again. If further adjustment does not solve the problem, try a different mask.
If your mask does not have an exhalation valve, you can also do the test while exhaling sharply.
Thomas is a new Assistant Professor of Behavior Science at the University of Chicago Booth School of Business and the founder of, a social enterprise to help people in China breathe clean air without shelling out thousands of dollars for expensive purifiers.