Tuberculosis Control Through Respirator Wear: Performance of National Institute for Occupational Safety and Health-Regulated Respirators

Details

• Personal Author:
  Qian Y ; Willeke K
• Description:
  In 1995 the National Institute for Occupational Safety and Health issued new rules for personal respirators. All nine new respirator categories are authorized in health care facilities for the prevention of the transmission of tuberculosis (TB). The new N95 respirator category is the most frequently used for this purpose. Data are presented on their efficiency for collecting TB-size bacteria and their potential for reaerosolizing collected bacteria. All measurements of bacterial penetration were performed with dynamic aerosol size spectrometers at flow conditions corresponding to normal wear and respirator certification conditions. The reaerosolization tests were performed at conditions ranging from normal breathing to violent coughing or sneezing. The tested N95 respirators collected 0.1 to 0.3 microm particles with efficiencies of 95% or higher, as specified by the regulations. TB-size bacteria of 0.8 microm and larger, however, were collected with 99.5% or higher efficiencies; that is, the penetration of these bacteria through the filter material was 0.5% or less, much less than the required maximum penetration of 5% for the smaller particle sizes. No bacteria were reaerosolized during normal exhalation. Some reaerosolization (0.1% or less) was observed only at low humidity and extremely high air flow through the respirator, corresponding to violent coughing or sneezing. The filter materials of N95 respirators provide good protection against TB bacteria. Thus, a significant number of bacteria can enter the respirator-wearer's breathing space only through spaces where the respirator inadequately seals to the wearer's face. Reentrainment and reaerosolization of mycobacteria is not a problem when normal work practices are observed in health care facilities. [Description provided by NIOSH]
• Subjects:
  Communicable Diseases Filtration Health Care Facilities Workforce And Services Occupational Health Personal Protective Equipment Respiratory Protective Devices Respiratory System Safety
• Keywords:
  Bacteria Disease-transmission Filters Health-care-facilities Infection-control Respirators Respiratory-equipment Respiratory-protection Respiratory-protective-equipment Safety-equipment
• ISSN:
  0196-6553
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  Ohio ; OSHA Region 5
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  139-142
• Volume:
  26
• Issue:
  2
• NIOSHTIC Number:
  nn:20030608
• Citation:
  Am J Infect Control 1998 Apr; 26(2):139-142
• Contact Point Address:
  Klaus Willeke, PhD, Aerosol Research and Exposure Assessment Laboratory, Department of Environmental Health, University of Cincinnati, P.O. Box 670056, Cincinnati, OH 45267-0056
• Federal Fiscal Year:
  1998
• Performing Organization:
  University of Cincinnati, Cincinnati, Ohio
• Peer Reviewed:
  True
• Start Date:
  19950201
• Source Full Name:
  American Journal of Infection Control
• End Date:
  19980731
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:8b255a3b18cc808052d4793f82a99e17620a7dd7c503806c8552a98d5a36ff025e11ab90cf919aeb7040c709a3ac1ccb60586872f3458025c5ea9de462112211
• Download URL:
  https://stacks.cdc.gov/view/cdc/191157/cdc_191157_DS1.pdf
• File Type:
  [PDF - 384.05 KB ]