I'm currently undergoing training to become an EMT-B and as we were going over basic equipment it occured to me that EMS uses an N95 mask for TB patients. Well I will assume bluntly that most TB's are also HIV patients. Those N95 masks are for non-oily particles of at least 300 nm in size, and here is where my question is. I dug up some info on some deadlier viruses from the net and their sizes: Bacteriophage MS-2 20nm Hepatitis 24nm - 30nm Adenovirus 70nm HIV (AIDS) 80nm Cytomegalovirus 100nm Orthomyxovirus 120nm Coronavirus (SARS) 80nm - 160nm It appears to me that the N95 or N99 or N100 or P99 - P100 masks wont protect anybody from any aforementioned viruses for respiratory contraptions. Furthermore, wearing a full face mask would probably be a wise choice over just goggles that have 2-5 mm gaps in between your eyes and nosal areas. And finally a medical set of hard gloves on top latex or nonlatex non sterile gloves, and perhaps some kind of an apron and a hair net. The information I've stumbled upon also suggests that the surgical masks arent quiet as effective as N95, meaning that most surgeons are not very safe from any aforementioned viruses. So my question is - what kind of a respirator should I use for TB/HIV/Hepatitis patients? Or what kind do they use at BSL-4?