Introduction to Antibacterial Principles of Medical Masks

Masks that can play a role in virus protection are mainly medical surgical masks and N95 masks. The national YY 0469-2004 "Technical Requirements for Medical Surgical Masks" standard stipulates that important technical indicators for medical surgical masks include filtration efficiency, bacterial filtration efficiency and respiratory resistance:

Filtration efficiency: Under the condition of air flow (30 ± 2) L / min, the filtration efficiency for aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 30%;
Bacterial filtration efficiency: Under specified conditions, the filtration efficiency for aerosols of Staphylococcus aureus with an average particle diameter of (3 ± 0.3) μm is not less than 95%;
Breathing resistance: In the condition of filtering efficiency and flow rate, the inhalation resistance does not exceed 49Pa, and the exhalation resistance does not exceed 29.4Pa.
Among them, the second criterion to ensure the bacterial filtration effect is the staphylococcus bacterial aerosol filtration efficiency of not less than 95%, which is the origin of the N95 concept. Therefore, although the N95 mask is not a medical mask, it meets the 95% filtration efficiency standard and can better fit the human face, so it can also play a good role in virus prevention.