A Multifaceted Evaluation on the Penetration Resistance of Protective Clothing Fabrics against Viral Liquid Drops without Pressure

Healthcare workers should wear appropriate personal protective clothing (PPC) on assuming the risk of exposure to various pathogens. Therefore, it is important to understand PPC performance against pathogen penetration. Currently, standard methods to evaluate and classify the penetration resistance of PPC fabrics with pressure using synthetic blood or phi-X174 phage have been established by the International Organization for Standardization (ISO). However, the penetration of viral liquid drops (VLDrop) on the PPC without pressure is also a major exposure route and more realistic, necessitating further studies. Here, we evaluated the penetration resistance against VLDrop without pressure using phi-X174 phage on woven and nonwoven fabrics of commercially available PPC classified by the ISO, and analyzed in detail the penetration behaviors of VLDrop by quantifying the phage amounts in leak-through and migration into test fabrics. Our results showed that some nonwoven test fabrics had nearly the same penetration resistance against VLDrop, even if the ISO resistance class differed. Furthermore, the results revealed that the amount of leakage through the fabrics was correlated with the migration amount into the fabric, which was related to fluid-repellency of fabrics, suggesting the effectiveness for penetration resistance. Our study may facilitate more appropriate selection for PPC against pathogen penetration.