N95 + test fit + don/doff procedures + change out at the end of service life would be a minimum for a threshold of "has a reasonable chance at being effective". I'd still want to see tests and studies.
By the time we're at single-ply spandex masks, we may as well have mandated plaid golf pants instead. Would be just as effective, and slightly less silly.
N95 are the only masks that can because they’re designed for viruses. This hokey pokey three ply shit only stops spit not air.
N95 + test fit + don/doff procedures + change out at the end of service life would be a minimum for a threshold of "has a reasonable chance at being effective". I'd still want to see tests and studies.
By the time we're at single-ply spandex masks, we may as well have mandated plaid golf pants instead. Would be just as effective, and slightly less silly.