ASTM Standards for Production and Testing of Medical Supplies to Combat COVID-19
astm.org
astm.org
"ASTM International ... is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services."
They're providing easier access to documents including test methods to evaluate face mask efficacy (ASTM F2101-19, ASTM F2299).
From there, you can either suffer digesting via watermarked-to-death PDF iframe, or download a copy of the unadulterated PDF for offline review.
They've listed 24 standards, but F1494 is a duplicate entry, and D5733 isn't actually linked to in their reading room (perhaps because it's a withdrawn standard). So really 22 standards avaiable.