I spent a lot of time working with patients who had hideously transmissible diseases or were at risk of getting hideously transmissible diseases, so I spent a lot of time in various types of personal protective equipment. Surgical masks are designed to keep stuff from flying out of your facial orifices and falling into the incision. Fabric or fiber masks seem to work fine for this application, and are also the usual choice for reverse isolation in non-surgical settings. Avoiding exposure to incoming infectious material requires more technology; N95 masks keep 95% of particulates out of your respiratory passages without being real tough to inspire through. tho I can't wear one if I am doing any active stuff, cause they don't let the air in and out fast enough. The best portable solution I have used was a tyvek hood with a battery powered hepa filtered fan (PAPR (powered air purifying respirator) that pushed filtered air into the hood-no fit issues, less claustrophobia, and plenty of air exchange. Spendy, though. But any of the lung-powered filtration units will place significant restriction on air movement, and will tire the user out pretty fast. The other issue is eye protection-the hood solves the problem, as doe the full face mask-but, since the eyes are not moving air in amd out like the respiratory bits, goggles provide significant protection, too. And all of it, and the wearer, need to be decontaminated before removal of the protective equipment.