title: Inward leakage in tight-fitting PAPRs.
abstract: A combination of local flow measurement techniques and fog flow visualization was used to determine the inward leakage for two tight-fitting powered air-purifying respirators (PAPRs), the 3M Breathe-Easy PAPR and the SE 400 breathing demand PAPR. The PAPRs were mounted on a breathing machine head form, and flows were measured from the blower and into the breathing machine. Both respirators leaked a little at the beginning of inhalation, probably through their exhalation valves. In both cases, the leakage was not enough for fog to appear at the mouth of the head form.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
authors.forename: Frank C
authors.initials: FC
authors.lastname: Koh
authors.forename: Arthur T
authors.initials: AT
authors.lastname: Johnson
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Rehak
mesh_terms: D000336:Aerosols / Q000032:analysis; D000395:Air Pollutants, Occupational / Q000032:analysis*; D004867:Equipment Design / Q000295:instrumentation / Q000379:methods; D005374:Filtration / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D016273:Occupational Exposure / Q000032:analysis*; D012119:Respiration; D012134:Respiratory Protective Devices / Q000145:classification / Q000592:standards*; D014741:Video Recording
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational