title: Impact of low filter resistances on subjective and physiological responses to filtering facepiece respirators.
abstract: Ten subjects underwent treadmill exercise at 5.6 km/h over one hour while wearing each of three identical appearing, cup-shaped, prototype filtering facepiece respirators that differed only in their filter resistances (3 mm, 6 mm, and 9 mm H2O pressure drop). There were no statistically significant differences between filtering facepiece respirators with respect to impact on physiological parameters (i.e., heart rate, respiratory rate, oxygen saturation, transcutaneous carbon dioxide levels, tympanic membrane temperature), pulmonary function variables (i.e., tidal volume, respiratory rate, volume of carbon dioxide production, oxygen consumption, or ventilation), and subjective ratings (i.e., exertion, thermal comfort, inspiratory effort, expiratory effort and overall breathing comfort). The nominal filter resistances of the prototype filtering facepiece respirators correspond to airflow resistances ranging from 2.1 - 6.6 mm H2O/L/s which are less than, or minimally equivalent to, previously reported values for the normal threshold for detection of inspiratory breathing resistance (6 - 7.6 mm H2O/L/sec). Therefore, filtering facepiece respirators with filter resistances at, or below, this level may not impact the wearer differently physiologically or subjectively from those with filter resistances only slightly above this threshold at low-moderate work rates over one hour.
authors.affiliation: Technology Research Branch, National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Roberge
authors.affiliation: Technology Research Branch, National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Jung-Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Technology Research Branch, National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Jeffrey B
authors.initials: JB
authors.lastname: Powell
authors.affiliation: Technology Research Branch, National Personal Protective Technology Laboratory, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, Pittsburgh, Pennsylvania, United States of America.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Shaffer
authors.affiliation: Personal Safety Division, 3M Company, St. Paul, Minnesota, United States of America.
authors.forename: Caroline M
authors.initials: CM
authors.lastname: Ylitalo
authors.affiliation: Personal Safety Division, 3M Company, St. Paul, Minnesota, United States of America.
authors.forename: John M
authors.initials: JM
authors.lastname: Sebastian
mesh_terms: D000328:Adult; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D010100:Oxygen; D010101:Oxygen Consumption; D012134:Respiratory Protective Devices; D056152:Respiratory Rate; D013997:Time Factors
chemical_list: D010100:Oxygen