Inhalation toxicity and skin irritation assessment of PVDF nanofiber-based breath mask filters

Abstract

The widespread adoption of nanofiber-based filtration systems, particularly in personal protective equipment, has drawn attention due to their exceptional filtration efficiency, high surface area, and structural similarity to biological membranes. However, despite their rapid commercialization, safety evaluation standards specific to nanofiber filters, especially those used in respiratory masks, remain limited. This gap raises concerns about potential health risks associated with prolonged inhalation exposure. The objective of this study was to assess the biological safety of electrospun polyvinylidene fluoride (PVDF) nanofiber filters used in commercial respiratory masks. To address this, we conducted a comprehensive in vivo evaluation involving skin irritation, intradermal reactivity, hemolysis, and a 30-day inhalation toxicity study using Wistar rats. Histopathological analysis of major organs, particularly the lungs, was performed to assess potential tissue-level effects. Key findings revealed no signs of dermal toxicity, systemic inflammation, or red blood cell hemolysis. Body weight and behavior remained stable throughout the exposure period, and histological examination showed no evidence of lung tissue damage or nanofiber accumulation. These results indicate that PVDF nanofiber filters are biocompatible and safe for respiratory applications. The findings support their continued use in protective masks and emphasize the importance of standardized safety evaluations for nanomaterial-based filtration devices.