Errors associated with three methods of assessing respirator fit

Count Plus with the N95-Companion) were evaluated for their ability to identify wearers of respirators that do not provide adequate protection during a simulated workplace test. Thirty models of NIOSH-certified N95 half-facepiece respirators (15 filtering-facepiece models and 15 elastomeric models) were tested by a panel of 25 subjects using each of the three fit testing methods. Fit testing results were compared to 5th percentiles of simulated workplace protection factors. Alpha errors (the chance of failing a fit test in error) for all 30 respirators were 71 % for the Bitrex method, 68 % for the saccharin method, and 40 % for the Companion method. Beta errors (the chance of passing a fit test in error) for all 30 respirator models combined were 8 % for the Bitrex method, 8 % for the saccharin method, and 9 % for the Companion method. The three fit test methods had different error rate