High-filtration masks only work when they fit – so we created a new way to test if they do
High-filtration masks only work when they fit – so we created a new way to test if they do: US 2015/Shutterstock During the pandemic, the prevailing thought has been that a high-filtration mask – such as an N95, KN95 or FFP3 – should offer better protection than a surgical or fabric mask. However, recent research …