Correlation of qualitative and quantitative results from testing respirator fit.

Three qualitative respirator fit tests were evaluated for their ability to adequately measure respiratory protection. The evaluated methods were the negative pressure test, the isoamyl acetate test, and the irritant smoke test. Each test was performed concurrently with a single quantitative fit test, the dioctylphthalate (DOP) test, during 274 half-mask and 274 full facepiece wearings. The quantitative values of DOP penetration obtained after passing or failing each qualitative fit test were lognormally distributed. For each qualitative test performed on each mask type, the average log penetration values obtained after passing and failing each test were statistically different from each other. The mean of the log penetration values associated with the failed qualitative test was always larger than the mean of the log penetration values associated with passed qualitative tests for all three qualitative methods. Most (95%) of the tested study had adequately fitting respirators as determined by quantitative testing. Of these subjects, 96% to 100% passed the qualitative fit tests. Of the 5% of the study subjects with inadequately fitting half mask respirators, 93% to 100% of the inadequate fits were detected by qualitative methods. Twenty three to 46% of the poorly fitting full face masks were detected by qualitative methods. The probability of passing or failing a qualitative test with an inadequately fitting respirator can be estimated; however, the uncertainty associated with each estimate is large due to the small number of study subjects with poorly fitting respirators.