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A quantitative fit test, condensation nuclei counting(Portacount 8025, TSI), was performed concurrently with a qualitative fit test, sodium saccharin(FT-10, 3M) to evaluate FF values and to determine the correlation between two methods. Two brands of full facepieces, T, S and two brands of half masks, T, S, were fit tested, respectively, on 103 wearers one time. The FF values obtained by CNC QNFT were lognormally distributed. The FF values for T brand of respirators were statistically very much higher than those for S brand of respirators. For a full facepiece wearer combination having a FF ≤ 100, as determined by CNC QNFT, the point estimate of the probability of that combination not being rejected by the saccharin QLFT was found to be 0.09 with 90% confidence that this statistic is not expected to exceed 0.25. For a half mask wearer combination having a FF ≤ 10, as determined by CNC QNFT, the point estimate of the probability of that combination not being rejected by the saccharin QLFT was found to be 0.10 with 90%, confidence that this statistic is not expected to exceed 0.23. The uncertainty associated with each estimate, however, is large due to the small number of study subjects with inadequately fitting respirators. This result indicates that saccharin QLFT may be more suitable for adequately fitting respirators than inadequately fitting respirators.
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