Use conditions of disposable masks
There are various kinds of disposable dust masks, which must be selected according to different operation requirements and working conditions.
Firstly, it should be selected according to the concentration and toxicity of dust. According to the selection, use and maintenance of respiratory protective equipment (GB / t18664), as a half mask, all dust masks are suitable for the environment where the concentration of harmful substances does not exceed 10 times of the occupational exposure limit, otherwise, a full mask or respirator with higher protection level should be used.
If the particles are highly toxic, carcinogenic and radioactive, the filter material with the highest filtration efficiency shall be selected.
If the particles are oily, be sure to select the appropriate filter material.
If the particles are needle like fibers, such as slag cotton, asbestos, glass fiber, etc., due to the dust mask can not be washed by water, the mask with micro fibers on the sealing part of the face is easy to cause facial irritation, and is not suitable for use.
For high temperature and humidity environment, the respirator with exhalation valve will be more comfortable. The respirator with ozone removal can be used for welding to provide additional protection. However, if the ozone concentration is higher than 10 times of the occupational health standard, the mask can be replaced with dust and poison combination filter elements. For the environment with no particles but only some peculiar smell, the dust mask with active carbon layer is much lighter than that with gas mask, such as some laboratory environment, but the national standard does not regulate the technical performance of this kind of mask.