N-95 filtering facepiece respirators (FFRs) appear to lose their fit after multiple successive donnings, according to a research team led by National Institute for Occupational Safety and Health (NIOSH) scientists. They studied six NIOSH-certified N-95 FFRs using 10 experienced wearers per respirator. The FFRs were tested for fit after each of up to 20 N-95 donnings, and the scientists then performed regression analyses for the percentage of donnings that scored a fit factor (FF) of 100 or higher, which was considered a passing grade. Donnings with a passing grade ranged from 81% to 93% for 1 to 5 donnings, 71% to 86% for 6 to 10 donnings, 62% to 83% for 11 to 15 donnings, and 53% to 75% for 16 to 20 donnings. The team also found that some models held up better during reuse. They summarize, "
The data suggest that 5 consecutive donnings can be performed before FFs consistently drop below 100." However, they underscore that this number does not constitute a recommendation, saying, "Further research is needed to better understand the limitations of FFR reuse, especially in actual workplace settings."
Aug 24
Am J Infect Control abstract
