There are three (3) defined levels of medical masks in the ASTM F2100 rating system. The difference between these masks is their performance criteria against F2100 International Standard requirements.
ASTM Level 1 masks are the general standard and are suited for environments that are both low-risk and low-fluid.
ASTM Level 2 masks are best used in environments that have moderate levels of fluid exposure.
ASTM Level 3 masks offer maximum barrier protection and work well in environments with high levels of fluid exposure.