Performance of surgical masks.
Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, Ohio 1995 Jun:14 pages
Surgical masks and respirators currently in use or being considered for use in the health care industry were evaluated. Collection efficiencies with bacteria were compared to those with inert, nonliving test particles currently used to evaluate the performance of industrial masks and respirators. If there was an adequate face seal fit of the mask to the face of the wearer, the findings indicated that higher efficiency filters in health care masks worked better. When there was a large face seal leak, the higher performance mask may actually perform worse than a less efficient mask, as the higher pressure drop across the higher performance mask directs more air flow through the face seal leak. Spherical Streptococcus-salivarius bacteria were able to penetrate as efficiently as inert corn-oil test particles in the size range from 0.9 to 1.7 micrometers. Less penetration was noted with rod shaped bacteria. The ratio of the length to the diameter of the bacteria was an important factor. A filter 95% efficient against spherical test particles may be 97 to 97.5% effective against Mycobacterium- tuberculosis bacteria. A respirator with only about 90% efficiency against spherical test particles or microorganisms would be needed to meet the regulation requiring 95% efficiency against rod shaped bacteria.
NIOSH-Grant; Respirators; Personal-protective-equipment; Respiratory-protection; Equipment-design; Equipment-reliability; Infection-control; Microorganisms
Environmental Health University of Cincinnati 3223 Eden Avenue Cincinnati, OH 45267-0056
Final Grant Report
NTIS Accession No.
Respirator Research; Respirators
Department of Environmental Health, College of Medicine, University of Cincinnati, Cincinnati, Ohio
University of Cincinnati, Cincinnati, Ohio