Method development for measuring respirator exhalation valve leakage.
Brueck S; Lehtimaki M; Krishnan U; Willeke K
Appl Occup Environ Hyg 1992 Mar; 7(3):174-179
The aim of this study was to develop a fast and inexpensive quality assurance test that measures air leakage through any leak sites in the respirator body; to compare this field compatible test to direct measurements of exhalation valve leakage; and to measure the leakage of air through new, unused exhalation valves and also through exhalation valves of respirators regularly worn and exposed to various workplace contaminants. Air flow through exhalation valves was measured at three different negative pressures. The Respirator Integrity Test and the Exhalation Valve Test were compared using fixed leak holes. Results showed that each test gave similar results if leakage occurred only through the exhalation valve. Leakage in most of the new exhalation valves tested was less than 10 cubic centimeters/minute, giving a flow ratio of 3200 which was considered insignificant. Some of the respirators used in a dusty industry had significant exhalation valve leakage. Respirators used in a chemical industry had insignificant exhalation valve leakage. Decreases in leakage ranged from 0 to 70% for new valves and 45 to 91% for field used valves.
NIOSH-Publication; NIOSH-Grant; Respiratory-protection; Chemical-cartridge-respirators; Personal-protective-equipment; Safety-equipment; Aerosol-particles; Airborne-dusts; Leak-prevention
Environmental Health University of Cincinnati Dept of Environmental Health Cincinnati, Ohio 45267
Applied Occupational and Environmental Hygiene
University of Cincinnati, Cincinnati, Ohio