Ak, your right the legalese is subject to interpretation and the OSHA standards are merely “minimum” standards at best. It is up to the individual to make a self preservation decision to do the RIGHT thing. The only respirators certified by NIOSH under Part 11 that meet CDC filtration efficiency performance criteria for protection against tuberculosis (TB) are those with HEPA filters. Health care delivery settings are generally free of oil aerosols that would be degrading to filter efficiency. Therefore, N-, R-, or P-series respirators are appropriate for protection against TB in health care settings and other workplaces in which oil aerosols are absent. HEPA filters are critical in the prevention of the spread of airborne bacterial and viral organisms and, therefore, infection. Typically, medical-use HEPA filtration systems also incorporate high-energy ultra-violet light units to kill off the live bacteria and viruses trapped by the filter media. Some of the best-rated HEPA units have an efficiency rating of 99.995%, which assures a very high level of protection against airborne disease transmission.