Comparison of Performance of Three Different Types of Respiratory Protection Devices

Respiratory protection is offered to American workers in a variety of ways to guard against potential inhalation hazards. Two of the most common ways are elastomeric N95 respirators and N95 filtering-facepiece respirators. Some in the health care industry feel that surgical masks provide an acceptable level of protection in certain situations against particular hazards. This study compared the performance of these types of respiratory protection during a simulated workplace test that measured both filter penetration and face-seal leakage. A panel of 25 test subjects with varying face sizes tested 15 models of elastomeric N95 respirators, 15 models of N95 filtering-facepiece respirators, and 6 models of surgical masks. Simulated workplace testing was conducted using a TSI PORTACOUNT Plus model 8020, and consisted of a series of seven exercises. Six simulated workplace tests were performed with redonning of the respirator/mask occurring between each test. The results of these tests produced a simulated workplace protection factor (SWPF). The geometric mean (GM) and the 5th percentile values of the SWPFs were computed by category of respiratory protection using the six overall SWPF values. The level of protection provided by each of the three respiratory protection types was compared. The GM and 5th percentile SWPF values without fit testing were used for the comparison, as surgical masks were not intended to be fit tested. The GM values were 36 for elastomeric N95 respirators, 21 for N95 filtering-facepiece respirators, and 3 for surgical masks. An analysis of variance demonstrated a statistically significant difference between all three. Elastomeric N95 respirators had the highest 5th percentile SWPF of 7. N95 filtering-facepiece respirators and surgical masks had 5th percentile SWPFs of 3 and 1, respectively. A Fisher Exact Test revealed that the 5th percentile SWPFs for all three types of respiratory protection were statistically different. In addition, both qualitative (Bitrex and saccharin) and quantitative (N95-Companion) fit testing were performed on the N95 filtering- and elastomeric-facepiece respirators. It was found that passing a fit test generally improves the protection afforded the wearer. Passing the Bitrex fit test resulted in 5th percentile SWPFs of 11.1 and 7.9 for elastomeric and filtering-facepiece respirators, respectively. After passing the saccharin tests, the elastomeric respirators provided a 5th percentile of 11.7, and the filtering-facepiece respirators provided a 5th percentile of 11.0. The 5th percentiles after passing the N95-Companion were 13.0 for the elastomeric respirators and 20.5 for the filtering-facepiece respirators. The data supports fit testing as an essential element of a complete respiratory protection program.

Keywords:

• N95 respirators
• respiratory protection
• simulated workplace protection factor
• surgical masks

ACKNOWLEDGMENTS

We acknowledge the following individuals for contributions to this article: John Odencrantz for statistical analysis; and Donna Simms, Howard Shen, Jeremy Myers, Jose Hernandez, Timothy Dawson, Tracey Prinsloo, and Yolanda Ward for helping to perform the respiratory protective device testing. We also thank Donald Campbell for his assistance in the development of the testing protocol.

Mention of commercial products or tradenames does not constitute endorsement by the Centers for Disease Control and Prevention or the National Institute for Occupational Safety and Health.

The findings and conclusions in this report are our own and do not necessarily represent the views of the National Institute for Occupational Safety and Health.

Notes

^AAll means having the same Duncan Grouping letter are statistically the same.

^AAll means having the same Duncan Grouping letter are statistically the same.

^AAll means having the same Duncan Grouping letter are statistically the same.

^BNot applicable.

^CNo subjects passed the fit test.

^AAll means having the same Duncan Grouping letter are statistically the same.