https://rdimedical.com/differences-between-astm-level-face-masks-2/
Level 2 and 3 Masks
If you are at a higher risk of being exposed to COVID-19 or more importantly, have been infected, the ASTM level 2 or 3 masks should be worn.
These will offer the best protection to others from the Coronavirus and ensure you are not cross-contaminating, provided you keep a reasonable distance from others.
