Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

Area of Science:

• Materials Science
• Analytical Chemistry
• Medical Device Sterilization

Background:

• The SARS-CoV2 pandemic led to critical shortages of surgical and FFP2 masks (equivalent to N95 masks).
• Efficient sterilization protocols are essential to reuse these vital personal protective equipment (PPE) items.
• Irradiation sterilization is a common method in the medical field, prompting its evaluation for mask decontamination.

Purpose of the Study:

• To investigate the molecular and macromolecular modifications induced by various sterilization processes on FFP2 masks.
• To evaluate the impact of irradiation under vacuum versus air, and gamma-rays versus electron beams (e-beams).
• To assess the effect of pre-washing followed by e-beam irradiation on mask material integrity.

Main Methods:

• Fourier transform infrared spectroscopy in attenuated total reflectance mode (FTIR-ATR) for molecular analysis.
• Size-exclusion chromatography (SEC) to assess macromolecular changes.
• Thermal-desorption-gas chromatography-mass spectrometry (TD-GC-MS) for detailed material characterization.

Main Results:

• Sterilization processes performed under vacuum induced relatively minor modifications to FFP2 mask materials.
• Irradiation using gamma-rays under air resulted in more significant molecular and macromolecular damage compared to vacuum methods.
• Pre-washing followed by e-beam irradiation also induced some material changes, requiring careful consideration.

Conclusions:

• Irradiation under vacuum appears to be a more suitable sterilization method for FFP2 masks, preserving material integrity.
• Gamma-ray irradiation in air poses a higher risk of material degradation, potentially compromising mask effectiveness.
• Further research is needed to optimize sterilization protocols balancing decontamination efficacy with material durability.