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Aerosol penetration behavior of respirator valves.

Brosseau LM

Am Ind Hyg Assoc J 1998 Mar; 59(3):173-180

https://doi.org/10.1080/15428119891010433

20030539

Exhalation and inhalation valves from half-facepiece negative pressure respirators were evaluated for leakage during an 8-hour cyclic breathing test period using two work rates (415 and 622 kg-m/min) and two particle sizes (0.3 and 0.8 micron). Three different models (manufacturers) of exhalation valves were tested, with two lots for each model. Exhalation valve leakage ranged from 0.0 to 0.03%; no failure of exhalation valves occurred. No differences in lot or manufacturer were found. Differences in particle size did not lead to differences in penetration at the lower work rate; at the higher work rate 0.3-micron particles were less penetrating than 0.8-micron particles (0.03 versus 0.06%). When tested for air leakage at a pressure of 2.54 cm H2O, following the National Institute for Occupational Safety and Health certification method, exhalation valves exhibited no leakage either before or after the experiments. Inhalation valves averaged 20% leakage for all experiments; 0.3-micron particles were again less penetrating (13%) than 0.8-micron particles (27%). No inhalation valve failure occurred. No differences in lot (within manufacturer) were found; there were, however, significant differences in particle penetration among the three manufacturers' inhalation valves. Airflow leakage through the inhalation valves did not change during the experimental period, but differed among the three manufacturers. Measurements using airflow leakage and particle penetration produced the same ranking for the three manufacturers' inhalation valves.

Aerosols; Respirators; Respiratory-equipment; Respiratory-protective-equipment; Models; Inhalation-studies; Air-flow; Respiration; Occupational-exposure

AIHAAP

19980301

Journal Article

30916

Grant

1998

Grant-Number-R03-OH-002806; Grant-Number-R03-OH-002938

3

0002-8894

American Industrial Hygiene Association Journal

MN

University of Minnesota Twin Cities, Minneapolis, Minnesota