A shortage of N95 masks in 2020 led the CDC to craft guidelines for healthcare workers who needed to reuse them for multiple shifts, but a new study, published Jan. 26 in JAMA, has found reuse of these masks can hurt their efficacy.
Researchers evaluated the effectiveness of three different varieties of N95 masks: dome, trifold, and duckbill that were tested for initial fit and after shifts of 412 healthcare workers. After one shift, across the board regardless of type, 38.7% of masks did not again fit properly for utmost protection.
Trifold N95s had the worst outcome after one shift, with a fit failure rate of 61.3% compared to just 28.3% for duckbill N95s and 25.8% for dome N95 masks.
While trifold N95s had the worst outcome after a single shift, all N95 mask types had a failure rate of 92.8% after being worn for five consecutive shifts.
"Our findings suggest that reuse of trifold N95s should be avoided," the researchers wrote. "[O]ur results add to concerns that efforts should be made to avoid critical PPE shortages as were experienced during the early COVID-19 pandemic."
They added that the study results are not restrictive to healthcare workplaces, but can be applied to "other workplaces, such as construction sites and industrial settings, where N95 respirator reuse may be practiced."