The protective efficiency of dust mask depends on two aspects:
First, the filtration efficiency of cotton filter;
The second is the air leakage rate after the mask is matched with the face;
Scientific selection of dust mask certified by GB2626-20 19 is helpful to prevent lung injury.
(1) Choose the compound semi-mask type: the disposable mask is not suitable for long-term or occupational protection due to its high air leakage rate;
(2) Choose KN 100 grade: low protection rate in high dust environment will lead to physical injury; KN refers to the protection of non-oily particles. The higher the latter value, the higher the protection level. KN 100 is the protection efficiency for particles above 0.075 micron, which can reach above 99.97%, and it is very suitable for use in high dust environment.
(3) Choose a mask made of silicone, which has a relatively long service life and is soft and comfortable. Long-term wear is not easy to cause allergic reactions; The mask with high hardness is easy to cause facial depression; Rubber is easy to wash and deform, but silica gel is not.
(4) The size of the mask is very important. It is not recommended to buy those so-called universal masks. Different people have different heights, shapes and faces. Of course, the universal model can't be close to everyone's face, and it is easy to leak.
(5) There are two kinds of masks covering the nose and mouth, covering the nose and mouth and the mandible. The latter is recommended, which is relatively comfortable;
(6) It is recommended to choose a respirator with smooth breathing: especially a dustproof respirator with double filter cotton and double filter surfaces, which has a longer service life and relatively smooth breathing.