Health Care Workers and Respiratory Protection: Is the User Seal Check a Surrogate for Respirator Fit-Testing?

Abstract

Many agencies recommend that health care workers wear N95 filtering facepiece respirators (N95-FFR) to minimize occupational exposure to bioaerosols, such as tuberculosis and pandemic influenza. Published standards outline procedures for the proper selection of an N95-FFR model, including user seal checks and respirator fit-testing. Some health officials have argued that the respirator fit-test step should be eliminated altogether, given its additional time and cost factors, and that only a user seal check be utilized to ensure that an adequate face seal has been achieved. One of the aims of the current study is to examine whether a user seal check is an appropriate surrogate for respirator fit-testing. Subjects were assigned an N95-FFR and asked to perform a user seal check (as per manufacturer's instructions) after which they immediately underwent a respirator fit-test. Successfully passing a respirator fit-test was based on not detecting a leakage through the face seal (either qualitatively with a test agent or quantitatively with a particulate counter). The sample population consisted of 647 subjects who had never been previously fit-tested (naïve), while the remaining 137 participants were experienced respirator users. Only four of the 647 naïve subjects (0.62%) identified an inadequate seal during their user seal check. Of the 643 remaining naïve subjects who indicated that they had an adequate face seal prior to fit-testing, 158 (25%) failed the subsequent quantitative fit-test and 92 (14%) failed the qualitative fit-test. All 137 experienced users indicated that they had an adequate seal after performing the user seal check; however, 41 (30%) failed the subsequent quantitative fit-test, and 30 (22%) failed the qualitative fit-test. These findings contradict the argument to eliminate fit-testing and rely strictly on a user seal check to evaluate face seal.

Keywords:

• health care workers
• N95 filtering facepiece respirators
• respirator fit-testing
• user seal check

Acknowledgments

This research is supported with funds from WorkSafeBC and the Workers' Compensation Board of Nova Scotia. The authors would also like to thank Lucy Budhoo from Fraser Health for her contributions in reviewing this article.