Impact of Decontamination Treatments on Surgical Mask Surface Properties and Their Role in Viral Biocontamination Risk

The widespread reuse of contaminated face masks during supply shortages has shifted global focus toward effective decontamination strategies. Since pathogen attachment is closely regulated by the physicochemical characteristics of mask fibers, any material alteration could compromise both filtration efficiency and safety. Despite this, the relationship between decontamination-induced surface changes and subsequent viral risk remains poorly understood. This study evaluates how ethanol, UV irradiation, and dry heat modify surgical mask surface properties and influence the predicted adhesion of three viruses: MS2, human adenovirus 5 (HAdV-5), and human respiratory syncytial virus (HRSV). Contact angle measurements and thermodynamic modeling were used to assess wettability, surface free energy, and virus-surface interaction energies (ΔGTotal). Results showed significant physicochemical modifications after treatments (p <; 0.001). UV and dry heat decreased the electron-acceptor component (γ+) from 21.5 to 0.2 and 1.8 mJ·m−2, respectively, while dry heat increased the electron-donor component (γ−) from 3.5 to 16 mJ·m−2. The Lifshitz-van der Waals component decreased across all treatments. UV irradiation caused the greatest variation in surface free energy, shifting from -10.89 to -78.9 mJ·m−2. Thermodynamic predictions indicated that dry heat consistently reduced viral adhesion, whereas ethanol and UV reduced MS2 adhesion but enhanced it for HAdV-5 and HRSV. These findings highlight the need for virus-specific decontamination strategies to ensure safe mask reuse.