Comparison of N95 disposable filtering facepiece fits using bitrex qualitative and TSI Portacount quantitative fit testing

As a means of evaluating the use of denatonium benzoate (bitrex) as a qualitative fit test agent with filtering facepiece respirators, the bitrex qualitative and TSI Protacount(R) quantitative fit-test methods were compared using N95 filtering facepieces. Seventy-nine paired tests (trial) were performed. Detection of bitrex during a qualitative fit test or measurement of a fit factor of <100 during a quantitative fit test constituted a failure. Qualitative and quantitative methods were performed using identical test protocols. Data were analyzed using pass/fail criteria, and matched-pair analysis methods were applied. The results of this study indicate that the use of bitrex during qualitative fit testing of N95 disposable filtering facepieces results in an increase in failure and/or rejection in cases where a TSI Portacount (plus N95 companion accessory) quantitatively establishes an acceptable fit.