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The effect of ambient aerosol concentration and exercise on Portacount quantitative fit factors.

Zhuang Z; Coffey C; Lawrence RB
J Int Soc Respir Prot 2004 Spring/Summer; 21(Spring/Summer):11-20
The PortaCount Plus Model 8020 is a quantitative fit test instrument that uses ambient aerosol to estimate respirator fit. Ambient aerosol concentration levels vary greatly among workplaces. The purpose of this study was to determine: (1) if PortaCount Plus fit factors are affected by ambient aerosol concentration; and (2) if any of the exercises are the most critical in determining the overall fit factor. Fit test data for 30 elastomeric and filtering-facepiece respirator models from a companion study were analyzed. Each respirator model was tested on a 25-subject panel using the PortaCount Plus and seven exercises. The analyses were conducted to determine: (1) if fit factor varies among five levels of ambient aerosol concentration; (2) the frequency of each exercise having the lowest within-fit-test fit factor among all exercises; and (3) the mean ratio of each exercise fit factor to the highest within-fit-test fit factor. Ambient aerosol concentration had no practical effect on fit factor. "Talking out loud," "bending," and "moving head up/down" exercises had the lowest fit factor in approximately 66% of the tests. They also had the lowest average within-fit-test ratios of exercise fit factor to the highest fit factor (0.56, 0.62, and 0.67, respectively). Fit factors for each exercise were found to be highly correlated with fit factors for each of the other six exercises. There was no significant fit-factor difference between the first and second normal breathing exercises. We conclude that the fit test pass/fail criterion need not be adjusted for ambient aerosol concentration level and that "talking out loud," "bending," and "moving head up/down" are the three most critical exercises in determining the overall fit factor. These three exercises could be considered for development of a multi-donning protocol using fewer and/or shorter exercises to keep the length of a fit test the same as the current fit test protocol.
Respirators; Air-pressure; Air-monitoring; Respiratory-equipment; Respiratory-irritants; Respiratory-protection; Respiratory-protective-equipment; Author Keywords: Quantitative Fit test; Fit Factor; Ambient Aerosol; PortaCount Plus; Exercise
Z. Zhuang, National Institute for Occupational Safety and Health, NPPTL, Pittsburgh, PA 15236
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Journal Article
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Journal of the International Society for Respiratory Protection
Page last reviewed: May 29, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division