Quantitative Fit Testing of Respirators: Past, Present, Future.
Fluid Filtration: Gas, Vol. I 1986;:181-192
Quantitative fit testing of respirators was discussed. The historical background of quantitatively measuring respirator fit was reviewed. The earliest methods used aerosols of bacteria or uranine dye. Neither method used extractive in/facepiece sampling. A technique was developed in the early 1960s that used sodium-chloride aerosols. Quantitative assessment of the respirator's performance was made by estimating the concentration of sodium-chloride in the exhaled air. From 1972 onwards, an improved quantitative fit method utilizing an oil mist of dioctyl-phthalate (DOP) or a polydisperse aerosol of sodium-chloride in conjunction with in/facepiece sampling and rapid response detectors and recorders was developed and employed. This technique provided a real time measurement of leakage into a respirator being worn by a human test subject. The oil mist method using DOP or other substances has become the method of choice for evaluating respirator fit in the United States. Current problems and research needs in quantitative fit testing of respirators were discussed. Research needs that have to be addressed included determining whether a respirator that gives the best fit in a quantitative fit test will provide the best protection in the workplace, whether fit factor data should be used as the basis for determining protection factors, and whether in/facepiece sampling as used in quantitative fit testing provides a representative sample. Data currently available have indicated that quantitative fit test data do not appear to be good predictors of workplace protection. The author states that assigned protection factors derived from fit test data tend to overestimate the protection offered, and in/facepiece sampling does not provide representative sampling.
Respiratory-protective-equipment; Occupational-health; Oil-mists; Aerosol-particles; Laboratory-testing; Humans; Laboratory-techniques; Health-protection; Leak-detectors;
Fluid Filtration: Gas, Vol. I