Noninvasive, quantitative respirator fit testing through dynamic pressure measurement.
Am Ind Hyg Assoc J 1988 Oct; 49(10):485-491
A noninvasive, quantitative method for the determination of respirator fit was described. The test was based on dynamic pressure measurements using breath holding at negative pressure for a few seconds to assess any pressure decay due to leaks inside the respirator cavity. A light weight pressure transducer attached to the respirator body monitored the pressure decay. The method was illustrated using experiments to determine the effect of sensor and leak location, leak hole size, and respirator cavity volume on the pressure decay of three different respirators. Evaluation of typical pressure decay curves obtained from testing the respirators with and without leak holes of different sizes and locations were presented, and pressure decay functions were described. Respirator fit was related to the equivalent diameter of respirator leaks which was a function of respirator volume and the measured leak slope. The authors note that the method is noninvasive, requires only a few seconds to perform, may be performed before and after actual respirator use, can be performed anywhere, is independent of leak and sensor location, is independent of aerosol deposition in the respiratory tract, can be used to determine the volume of the respirator cavity, and can be used on any type of respirator in which the airflow can be interrupted for a few seconds.
NIOSH-Publication; NIOSH-Grant; Screening-methods; Equipment-design; Personal-protective-equipment; Air-purifying-respirators; Respiratory-protective-equipment; Aerosol-particles
Environmental Health University of Cincinnati Dept of Environmental Health Cincinnati, Ohio 45267
American Industrial Hygiene Association Journal
University of Cincinnati, Cincinnati, Ohio