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A comparison of controlled negative pressure and aerosol quantitative respirator fit test systems by using human subjects.

Authors
Crutchfield CD; Murphy RW; Ert MD
Source
Am Ind Hyg Assoc J 1993 Jan; 54(1):10-14
NIOSHTIC No.
00212480
Abstract
Negative pressure and aerosol systems for fit testing of respirators on human subjects were compared. Subjects wore small, medium, or large size half mask or full facepiece probed respirators for the conducting of fit tests. By removing the cartridges and installing airtight manifolds in the cartridge receptacles, negative pressure tests were accomplished. Repeated sequential fit tests were conducted on a single subject using both fit test systems. Repeated testing was conducted on three subjects over a 1 month period with both half mask and full face respirators. Sequential fit tests were conducted for 125 military and civilian workers in a respiratory protection program using both negative pressure and aerosol tests. The controlled negative pressure system consistently detected a range of air leakage through fixed leaks and respirator face seals. The aerosol system results were in general an order of magnitude lower than those determined by the negative pressure tests. An assumed inspiratory flow of 431 milliliters/second was used to calculate the negative pressure determined fit factors. Relatively low levels of challenge aerosol were detected in the mask sampling line. The authors suggest that other factors such as leak penetration losses, incomplete mixing due to streamlining, and lung retention may have been important contributors to the reduced aerosol levels detected. The authors conclude that the aerosol fit test systems may seriously underestimate air leakage into respirators.
Keywords
NIOSH-Publication; NIOSH-Grant; Respirators; Respiratory-protective-equipment; Humans; Personal-protective-equipment; Equipment-reliability; Respiratory-equipment; Face-masks
Contact
Pharmacology and Toxicology University of Arizona 1435 N. Fremont Ave Tucson, AZ 85721
CODEN
AIHAAP
Publication Date
19930101
Document Type
Journal Article
Funding Amount
97144
Funding Type
Grant
Fiscal Year
1993
Identifying No.
Grant-Number-K01-OH-00068
Issue of Publication
1
ISSN
0002-8894
Source Name
American Industrial Hygiene Association Journal
State
AZ
Performing Organization
University of Arizona, Tucson, Arizona
Page last reviewed: May 11, 2023
Content source: National Institute for Occupational Safety and Health Education and Information Division