The filtration performance of fabrics against particles of viral size: a systematic review.

Introduction: Wearing a mask is part of the comprehensive strategy to suppress transmission of the SARS-CoV-2 virus and respiratory tract infections. Despite available COVID-19 vaccines, wearing a mask has remained one of the simplest and most effective ways. There was, however, little data available regarding the filtration of fabrics in masks against infectious aerosols or particles of viral size. This study reviewed the filtration performance of fabrics against virus-sized particles.

Methods: The systematic review was conducted according to the PRISMA 2020 statement. The literature search started with seven electronic databases (PubMed, Google Scholar, Scopus, Institute of Science Index, EMBASE, Cochrane Library, SciFinder) and two preprints, then manual search. Quality assessment was performed on all included studies using an adaptive tool for in vitro studies.

Results: Eighteen studies were finally included. Cotton was most commonly investigated, followed by polymers and nanofibers. A study reported filtration performance as droplet blocking efficiency (%), and materials with the highest blocking efficiency comprised polypropylene (99.7 [95.2-99.9]), cotton (98.9 [96.8-99.8]), silk (98.7 [81.1-99.8]), and polyester/polyamide (98.2 [90-99.8]). Other studies reported filtration efficiency (%). Fabrics showing highest filtration efficiency were polymers (polypropylene, polyethylene, spunbond/meltblown/spunbond) (100, 94.4, 93.9, respectively), nanofibers (nanofiber-fabric-layered composite, polyvinyl alcohol/nylon-taffeta composite) (99.8 ± 0.24, 97.3, respectively), cotton (cotton/chiffon, cotton quilt, cotton/flannel, cotton/silk) (97 ± 2, 96 ± 2, 95 ± 2, 94 ± 2, respectively). Quality assessment showed that most of the studies were adequate to evaluate the filtration performance against aerosol or virus particles.

Conclusion: Some fabrics showed effectiveness in protective applications for respiratory infections; particularly nanofibers and polymers were promising materials for specialized masks or respirators.