Except that field data shows they don’t because they are not used precisely as required - which means the filter doesn’t work effectively if at all and then it

Except that field data shows they don’t because they are not used precisely as required - which means the filter doesn’t work effectively if at all and then it becomes infectious waste that isn’t treated and disposed of correctly. Human system effects dominate - as the field data shows. It’s like HCQ - works in a lab, not in the real world. Might be useful in tightly controlled medical settings with adequate filtered ventilation. But there’s no hard evidence beyond that at this stage. Feynman’s rule still applies.