Comment Submitted by: Andrew W. Varner for University of Pittsburgh Medical Center

As a safety professional for a healthcare system, I annually perform approximately 750 qualitative fit tests on employees wearing a variety of N95 respirators, Kimberly Clark, 3M and Moldex being the most common brands. The results found in the study by Nelson, T.J., L.L. Janssen, M.D. Luinenberg, and H.T. Mullins are consistent with the experiences I have had in fit-testing. I typically find that a poor respirator fit is noticed almost immediately. Sometimes it is not noticed until a particular phase of the test, such as when the head is nodded up and down, but, it is typically noticed early in the phase. Occassionally I find a mask that appears to be sized correctly and fit well and yet the wearer still tastes the solution at some point in the test. When this happens I have found that by re-training, spending some time with person on better molding of the nose piece and head band placement, I can often enable the wearer to achieve a satisfactory fit with that respirator. In other words, the mask was satsifactory, the fit test procedure worked fine, it was the training program that was initially deficient and therefore additional time should have been dedicated to training versus fit testing. Simply put, my experience is that a brand of mask will either fit or it will not and it does not take long to figure that out, especially with bitrex. I support the abbreviated fit test time. University of Pittsburgh Medical Center, Andrew W. Varner