DEVELOPMENT OF A NEW QUALITATIVE TEST FOR FIT TESTING RESPIRATORS

A new qualitative fit test was developed using Bitrex(TM) (Macfarland Smith limited) as the rest agent. it was validated by running a series of paired qualitative and quantitative fit tests. Quantitative tests were conducted with a small corn oil aerosol, using a condensation nuc leus counter as a detector. Qualitative fit tests were run with Bitrex and saccharin, following the established protocol for the saccharin f it test. Four models of National institute for Occupational Safety aci d Health-approved replaceable filter respirators were used in the stud y. Ail were half mask models equipped with high efficiency filters. in some cases, respirators expected to be the correct size for lest subj ects were tested. In other cases, respirators expected to be too small or too large for the subjects were rested. rest results were analyzed using fit lest method validation criteria recommended in the American National Standards Institute draft standard on fit testing (ANSI Z88. 10). The Bitrex and saccharin tests were found to have virtually ident ical performance. Both met proposed American National Standards instit ute requirements for a valid qualitative fit test.