Failure Rates During Reuse of Disposable N95 Masks in Clinical Practice in the Emergency Department

Area of Science:

• Occupational Health
• Infectious Disease Control
• Respiratory Protection

Background:

• The COVID-19 pandemic led to a critical shortage of disposable N95 respirators.
• Healthcare facilities extended N95 respirator use beyond single-use recommendations due to scarcity.
• Limited research supported the safety and efficacy of reusing N95 masks.

Purpose of the Study:

• To evaluate the failure rates of disposable N95 respirators upon reuse in a clinical setting.
• To assess the accuracy of healthcare workers' subjective assessment of N95 mask seal integrity.

Main Methods:

• A prospective cohort study involving 127 healthcare workers (HCWs) in an academic emergency department.
• Periodic fit testing of N95 masks throughout shifts over an eight-week period.
• Collected data included mask age, subjective seal quality assessment, and objective fit test results.

Main Results:

• Mask failure rates significantly increased after the second day of use, reaching 50% by day five.
• Masks used for three or more days had a 7.9 times higher odds of failure compared to those used for two days or less (41.8% vs 8.3%).
• Healthcare workers' subjective assessment of poor seal had low sensitivity (33.3%) but high specificity (95.7%) for detecting fit test failure.

Conclusions:

• Disposable N95 masks demonstrate substantial failure rates when reused in clinical practice.
• Healthcare personnel exhibit poor performance in subjectively assessing the seal integrity of their respirators.
• Findings underscore the risks associated with N95 respirator reuse and the unreliability of self-assessment for mask fit.