Reuse of N95/PFF2 masks in clinical practice: morphological and structural analysis

Abstract

Objective: to analyze the integrity of N95/PFF2 masks in relation to fiber morphology, porosity, cracks and micro holes, as well as identify visible damage to their structure and components, after seven- and fifteen-day reuse protocols. Method: cross-sectional study. Structural and morphological characteristics of a new N95/PFF2 mask were analyzed in comparison with N95/PFF2 masks (n=10) used in seven- and fifteen-day protocols, through visual inspection and scanning electron microscopy. Results: upon visual inspection, following the seven-day protocol, 40% and 60% of the N95/PFF2 masks showed, respectively, personal identification marks and external and internal dirt. Additionally, 20% exhibited loosening and/or tearing of the straps, while 100% showed some type of damage to the nose clips. In the fifteen-day protocol, all N95/PFF2 masks had dirt, loose straps and damaged nose clips, and 80% had folds. Electronic microscopy revealed an increase in pores and loosening in the weaves from seven days onwards, extending up to fifteen days, with the presence of micro holes and residues. Conclusion: the reuse of N95/PFF2 masks affects their structural and morphological integrity. It is crucial to carry out tests to measure the impact of this practice on the safety of health professionals.