Is it necessary to wear a hepa mask in a room where a suspected TB patient is intubated and on a ventilator with a hepa filter over the exhalation port? Obvously if the circuit is broken a hepa mask should be worn, but if the circuit is not broken, is a hepa mask really needed? Any information, research, advice or other wisdom greatly appreciated so we can adjust our policy in accordance to common sense. The present policy requires a hepa mask be worn regardless.