According to the performance characteristics and scope of application, medical masks can be divided into medical protective masks, medical surgical masks and ordinary medical masks.
1. Medical protective masks
In line with gb19083-2003 technical Requirements for Medical Protective Masks, important technical indicators include non-oily particle filtration efficiency and airflow resistance:
(1) Filtration efficiency: under the condition of air flow rate of (85±2)L/min, the filtration efficiency of the aerodynamics median diameter of (0.24±0.06)μm sodium chloride aerosol is not less than 95%, that is, in line with N95(or FFP2) and above grade.
(2) Suction resistance: under the above flow conditions, the suction resistance does not exceed 343.2Pa(35mmH2O).
2. Surgical masks
It conforms to the standard of YY 0469-2004 technical Requirements for Medical Surgical Masks, and the important technical indexes include filtration efficiency, bacterial filtration efficiency and respiratory resistance:
(1) Filtration efficiency: under the condition of air flow rate (30±2)L/min, the filtration efficiency of sodium chloride aerosol with aerodynamic median diameter (0.24±0.06)μm is not less than 30%;
(2) Bacterial filtration efficiency: under specified conditions, the filtration efficiency of staphylococcus aureus aerosol with an average particle diameter of (3±0.3)μm is not less than 95%;
(3) Respiratory resistance: under the condition of filtration efficiency flow, inspiratory resistance shall not exceed 49Pa, and expiratory resistance shall not exceed 29.4Pa.
3. Ordinary medical masks
In accordance with the relevant registered product Standards (YZB), generally lacks the filtering efficiency requirements for particles and bacteria, or the filtering efficiency requirements for particles and bacteria are lower than those for medical surgical masks and medical protective masks.