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Evaluation of the filtration performance of 21 N95 filtering facepiece respirators after prolonged storage.
Viscusi-DJ; Bergman-M; Sinkule-E; Shaffer-RE
Am J Infect Control 2009 Jun; 37(5):381-386
Background: Organizations are stockpiling respirators to prepare for an influenza pandemic. To better understand the effects of prolonged storage, this investigation evaluated the filtration efficiency of 21 different models of National Institute for Occupational Safety and Health (NIOSH)-certified disposable N95 filtering facepiece respirators. These respirators had been stored in their original packaging for a period of at least six years in research laboratories and dry warehouse facilities, ranging in temperature between 15 degrees C-32 degrees C and relative humidity between 20-80%RH. Methods: Filter penetration was measured using an abbreviated version of the NIOSH respirator certification test incorporating a polydisperse sodium chloride aerosol at 85 L/min. Results: Of the 21 respirator models tested, 19 models had both average penetration results of less than 5%. Mean initial penetration values ranged from 0.39% to 5.83%, while mean maximum penetration values ranged from 0.95% to 5.83%. There did not appear to be any correlation between the length of storage and failure to pass the filtration test. Conclusions: Results indicate that most N95 filtering facepiece respirators stored for up to ten years at warehouse conditions will likely have expected levels of filtration performance and the degree of filtration efficiency degradation is likely model specific.
Filters; Filter-materials; Filter-fabrics; Respirators; Respiratory-protective-equipment; Personal-protective-equipment; Personal-protection; Infectious-diseases
Ronald E. Shaffer, Ph.D., Chief, Technology Research Branch, National Personal Protective Technology Lab (NPPTL), National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC), 626 Cochrans Mill Road, Bui
Issue of Publication
Healthcare and Social Assistance
American Journal of Infection Control
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division