Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

NIOSHTIC-2 Publications Search

Search Results

Tuberculosis control through respirator wear: performance of National Institute for Occupational Safety and Health-regulated respirators.

Authors
Willeke-K; Qian-Y
Source
Am J Infect Control 1998 Apr; 26(2):139-142
NIOSHTIC No.
20030608
Abstract
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.
Keywords
Respirators; Respiratory-equipment; Respiratory-protection; Respiratory-protective-equipment; Safety-equipment; Bacteria; Health-care-facilities; Filters; Filtration; Disease-transmission; Infection-control
Contact
Klaus Willeke, PhD, Aerosol Research and Exposure Assessment Laboratory, Department of Environmental Health, University of Cincinnati, P.O. Box 670056, Cincinnati, OH 45267-0056
CODEN
AJICDC
Publication Date
19980401
Document Type
Journal Article
Funding Amount
746102
Funding Type
Grant
Fiscal Year
1998
NTIS Accession No.
NTIS Price
Identifying No.
Grant-Number-R01-OH-003244
Issue of Publication
2
ISSN
0196-6553
Source Name
American Journal of Infection Control
State
OH
Performing Organization
University of Cincinnati, Cincinnati, Ohio
TOP