Recent study on 3-Ply cotton masks vs. Medical masks.
This is quite a nerdy read, but the takeaway is that all the tested masks (3-ply cotton, medical surgical and medical respirator) will protect others from the wearer even in air-conditioned or in-car environments. The medical respirator performs the best in protecting the wearer and the medical surgical mask comes in 2nd place, which is still 3X better than a 3-ply cotton mask.
This goes along with what we say throughout our site is that in low risk situations, a reusable mask like our 3-ply cotton will be good for conservation sake. However, nothing beats the medical masks and respirators like our Level 3 and FDA approved KN95.
Take a read!