In theory, an N95 mask should work. At its weak spot - .1 microns or so - it’s still 95% effective. It’s been shown to be 95% vs NaCl, which is smaller than ble

In theory, an N95 mask should work. At its weak spot - .1 microns or so - it’s still 95% effective. It’s been shown to be 95% vs NaCl, which is smaller than bleach (NaOCl). But in personal experience, whenever I finish up with a patient in contact isolation, I use bleach wipes on my steth. Not only does the odor strongly penetrate the mask, but by mitigating the dilution effect of free air flow, I honestly feel like it concentrates more of the crap inside the mask. For whatever anecdote is worth.