Use of a surgical mask as an outer barrier over N95 filtering facepiece respirators does not significantly impact the physiological burden or perceptions of comfort and exertion by the wearer over that experienced without use of a surgical mask.

The objective of this study was to determine if ultraviolet germicidal irradiation (UVGI), moist heat incubation (MHI), or microwave-generated steam (MGS) decontamination affects the fitting characteristics, odor, comfort, or donning ease of six N95 filtering facepiece respirator (FFR) models. For each model, 10 experienced test subjects qualified for the study by passing a standard OSHA quantitative fit test. Once qualified, each subject performed a series of fit tests to assess respirator fit and completed surveys to evaluate odor, comfort, and donning ease with FFRs that were not decontaminated (controls) and with FFRs of the same model that had been decontaminated. Respirator fit was quantitatively measured using a multidonning protocol with the TSI PORTACOUNT Plus and the N95 Companion accessory (designed to count only particles resulting from face to face-seal leakage). Participants' subjective appraisals of the respirator's odor, comfort, and donning ease were captured using a visual analog scale survey. Wilcoxon signed rank tests compared median values for fit, odor, comfort, and donning ease for each FFR and decontamination method against their respective controls for a given model. Two of the six FFRs demonstrated a statistically significant reduction (p< 0.05) in fit after MHI decontamination. However, for these two FFR models, post-decontamination mean fit factors were still ≥ 100. One of the other FFRs demonstrated a relatively small though statistically significant increase (p < 0.05) in median odor response after MHI decontamination. These data suggest that FFR users with characteristics similar to those in this study population would be unlikely to experience a clinically meaningful reduction in fit, increase in odor, increase in discomfort, or increased difficulty in donning with the six FFRs included in this study after UVGI, MHI, or MGS decontamination. Further research is needed before decontamination of N95 FFRs for purposes of reuse can be recommended.

No abstract

After 1 hour of exercise in hot, humid ambient conditions, P100 FFRs retained better fit than N95 FFRs, without additional physiologic or subjective impact. Wearing FFRs under these conditions does not add to the body's thermophysiologic or perceptual burdens.