Reuse of N95 respirators: a systematic review on effectiveness and occupational safety for healthcare professionals.

Objective: To analyze the evidence on the effectiveness of extended use and reuse protocols of N95 respirators, with a focus on the occupational safety of healthcare professionals.

Method: Systematic review of articles published between 2003 and 2024 in the Medline/PubMed, Web of Science, SCOPUS, Embase, and CENTRAL databases. Experimental, quasi-experimental and observational studies were included. Methodological quality was assessed using the Joanna Briggs Institute tool. Narrative synthesis was used to present the results.

Results: The review encompassed 21 articles. The most investigated aspect was sealing (71.4%), followed by structural integrity (33.3%), filtration efficiency (19.0%), and, finally, tensile testing of the fastening straps (4.8%). Damage such as dirt accumulation, broken nose clips, and strap breakage, as well as degradation of elastic resistance, were observed, leading to inadequate fit and reduced filtration capacity. Four studies were classified as high quality, while 17 were of moderate quality.

Conclusion: Extended use and reuse of N95 respirators are not recommended, as they increase occupational risk. Although they maintain adequate filtration efficiency in different contexts, this is not sufficient to ensure user protection. When unavoidable, strict evidence-based protocols must be followed.