How long can an individual continue to use a single N95 or other fitted respirator?
Although designated as “single use”, N95 respirators can be used continuously for an entire shift as long as there is no gross soiling of the mask and fit and ease of breathing are unimpaired. Paper procedure masks or surgical masks (FDA-approved for the OR environment) have been used over the top of an N95 to decrease soiling. This does increase the workload, but is fine as long as the work of breathing is tolerated.
Recommended guidance for extended use and limited reuse of N95 filtering facepiece respirators in healthcare settings. CDC/NIOSH. Accessed on May 6, 2020 at: https://www.cdc.gov/niosh/topics/hcwcontrols/recommendedguidanceextuse.html