"Things You Wouldn't Know If We Didn't Blog Intermittently."
28 June 2020
Valved masks are NOT appropriate for coronavirus
A valved mask decreases the work of breathing (on expiration) for those who labor in dusty environments, but the facilitated exit of expired air runs counter to the need to protect others during the pandemic.
Also worth noting that the "KN95" designation does NOT mean that this is an "N95" mask with optimal filtering. The KN is a manufacturer's name for the product, designed to be deceptive to buyers.