In-depth measurement of the efficiency of medical face masks used by healthcare workers to mitigate respiratory infection

Abstract

Background: The coronavirus pandemic increased reliance on medical face masks as a first-line protective measure in healthcare settings, yet concerns remain regarding the quality of uncertified products circulating in the market. This study aimed to evaluate the protective performance of medical face masks used by healthcare workers in Iran against the requirements of EN 14683. Methods: Ten brands of uncertified masks (Test Samples) and five certified masks (Reference Samples) were examined. Custom experimental test setups were developed to measure bacterial filtration efficiency (BFE) and differential pressure (Pa/cm(2)), and the morphology of the meltblown layer was analyzed using scanning electron microscopy (SEM) and ImageJ. According to EN 14683:2019 + AC:2019, Type I masks require bacterial filtration efficiency (BFE) >= 95, whereas Type II masks require BFE >= 98; both classes require differential pressure <40 Pa/cm(2). Results: The Test Samples showed lower BFE, lower quality factor, and less favorable meltblown structural characteristics than the Reference Samples. When evaluated against the Type I criterion, three out of ten Test Sample brands (30) met the BFE requirement, while none met the Type II criterion of >= 98. All Reference Samples satisfied the Type I criterion (BFE >= 95), whereas only two Reference Sample brands met the Type II criterion (BFE >= 98). Positive correlations were observed between BFE and meltblown grammage, whereas fiber diameter was negatively associated with porosity. Conclusions: These findings highlight the critical role of meltblown layer quality and the importance of routine post-market surveillance to ensure healthcare worker protection. The results indicate that several uncertified masks used by healthcare workers do not provide consistent performance and should not be assumed to meet international medical mask standards. (c) 2026 The Authors. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).