How long can medical masks last
Medical masks are normally used for about one day. The medical mask is composed of a mask face and a tension band. The face mask is divided into inner, middle and outer layers, the inner layer is skin-friendly material, the middle layer is an isolation filter layer, and the outer layer is a special material antibacterial layer. This highly effective medical mask is highly hydrophobic and breathable, and has a significant filtering effect on micro-band virus aerosols or harmful dust, but cannot effectively filter PM10 and PM2.5. The overall filtering effect is good, and the materials used are non-toxic and harmless to wear and comfortable.
According to performance characteristics and scope of application, medical masks can be divided into: medical protective masks, medical surgical masks, general medical masks.
1. Medical protective masks: in accordance with GB19083-2003 "Technical Requirements for Medical Protective Masks". Important technical indicators include non-oily particle filtration efficiency and airflow resistance: (1) Filtration efficiency: at air flow (85 ± 2) L / min Below, the filtration efficiency of aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 95%, that is, it meets N95 (or FFP2) and above.
(2) Inspiratory resistance: Under the above flow conditions, the inspiratory resistance does not exceed 343.2Pa (35mmH2O).
2. Medical surgical masks: in line with YY 0469-2004 "Technical Requirements for Medical Surgical Masks", important technical indicators include filtration efficiency, bacterial filtration efficiency and respiratory resistance: (1) filtration efficiency: at air flow (30 ± 2) L / Under the condition of min, the filtration efficiency for aerodynamic median diameter (0.24 ± 0.06) μm sodium chloride aerosol is not less than 30%;
(2) Bacterial filtration efficiency: Under specified conditions, the filtration efficiency of S. aureus aerosols with an average particle diameter of (3 ± 0.3) μm is not less than 95%;
(3) Breathing resistance: under the condition of filtering efficiency and flow rate, the inhalation resistance does not exceed 49Pa, and the exhalation resistance does not exceed 29.4Pa.
3. Ordinary medical masks: meet the relevant registered product standards (YZB), and generally lack the filtration efficiency requirements for particles and bacteria, or the filtration efficiency requirements for particles and bacteria are lower than medical surgical masks and medical protective masks.