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Storage and handling of respirators challenged with M. Tuberculosis (MTB): measures fo interior and exterior contamination over time.

Johnson B; Winters D; Shreeve T; Coffey C
American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 1997 May; :83-84
All respirators certified under 42 CFR Part 84 can be considered for issue to health care workers as personal protective devices against exposure to MTB. Questions have been raised regarding the possibility of the respirator becoming contaminated with MTB or other organisms due to reuse, handling, and storage in plastic bags. This study was conducted to (1) determine whether, and for how long, MTB (H37RA) survives on respirator material; (2) assess levels of contamination with environmental bacteria and fungi due to storage in airtight bags; and (3) measure levels of contamination potentially spread to the interior surface of the respirator due to normal mechanical handling (removal and reinsertion of the respirator in the bag). Six models of disposable respirators were challenged with a concentration of 10 to the 5th to 10 to the 6th CFU MTB/ L air in a steady flow system. Respirator interior and exterior surfaces were swab sampled on days -1 (prior to exposure), 0 (exposure), 1, 3, 7, 10, 14, 21, and 28. Between sampling, each respirator was stored at room temperature in a zip-lock bag. Seven days after exposure the number of viable organisms decreased from a mean range of 27-131 CFU/cm2 to 0 CFU/ cm2 for the different respirator models. No transfer of exterior MTB was observed from day 0·10; however, some colony growth was recoverable from day 14-28, indicating there may be some environmental contaminants (bacterial and fungi) mechanically transferred to the interior of the respirator after repeated handling and long-term storage.
Respirators; Health-care-personnel; Personal-protective-equipment; Exposure-levels; Air-contamination; Organic-compounds; Bacteria; Face-masks; Air-flow; Environmental-contamination; Environmental-exposure; Environmental-factors; Environmental-hazards; Storage-containers; Infection-control; Infectious-diseases
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American Industrial Hygiene Conference and Exposition, May 19-23, 1997, Dallas, Texas
Page last reviewed: March 25, 2022
Content source: National Institute for Occupational Safety and Health Education and Information Division