(Web Desk) - Consistently reusing N95 respirators could limit their effectiveness, a new study finds.
Nearly 40% of N95 masks lose some of their protective properties after being used by a healthcare worker for just one shift, a study published last week in JAMA found.
N95 respirators, which are considered the gold standard when it comes to masks in clinical settings, are typically disposed of after each encounter with a patient.
However, during the height of the COVID-19 pandemic, supply shortages resulted in health care workers having to reuse some of their personal protective equipment.
During this time, the Centers for Disease Control and Prevention (CDC) revised its guidelines on N95 use to allow for extended use and limited reuse to preserve supplies. However, the changes were made with minimal evidence on how reusing the masks affected their function.
This latest research confirms what experts had feared — that extended use of N95s lessens their protective effects.
For the study, researchers compared three different types of N95s: dome, duckbill and trifold. The masks were fit tested on a total of 412 health care workers at the start of their shift, and then again two more times after their first and fifth shifts to assess the mask’s fit after extended use.
After just one shift, 38.7% of the masks no longer fit the workers appropriately. Fit failure was observed in 25.8% of the dome masks and in 28.3% of the duckbill types, while the trifold masks deteriorated at significantly higher rates, at 61.3%.
After five shifts, nearly 93% of the masks no longer passed the fit test.
N95s are fitted in a way that prevents the transmission of viral particles, reducing the risk that users will acquire a viral infection. When they do not fit properly, they are much less protective.
If a physician or health care worker is donning an ill-fitting mask, they are at greater risk of not just acquiring a viral illness themselves, but also exposing vulnerable patients to viral particles as well.
The researchers suggest that their findings call into question the safety of repeated N95 use, especially the trifold type, which the authors said should not be used for an extended amount of time.
Although reusing N95s was a necessary move during supply shortages, the researchers say that the masks’ performance in their study should be used to inform adjustments to future pandemic preparedness initiatives.