The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) has published standards for Indoor Air Quality (ASHRAE 62.1 & 62.2) and Control of Infectious Aerosols (ASHRAE 241).
I've done a first pass over the numbers published in ASHRAE 241, converting the cited numbers for various scenarios to cubic meters of clean air per person per hour. Then compared that to some of the air filters I've been looking at recently:
