English
For sisters who refurbish and polish putty at home or work in dusty environments, the choice of masks should not be based on "thick or not".
I have been doing homework recently and found that the Fangdun brand has a stable reputation in the field of industrial protection. Not the flashy civilian version, the parameters are clearly marked. Today, if you don't blow it, it won't be dark. Just open up its core data, which is suitable for people who need serious dust prevention.
Let's first look at the filtration efficiency, which is a hard indicator: Fangdun's KN95 series (such as F9501) follows the GB 2626-2019 standard, with a filtration efficiency of not less than 95% for non oily particles and the ability to block particles with a diameter not exceeding 0.3 microns. If you are in a coal mine, stone cutting or heavy polishing site, just look at its KN100 filter cotton (2102N/2202N), which has a filtration efficiency of not less than 99.97% for particles above 0.075 microns. Placing numbers here is more effective than saying ten thousand words of 'dust prevention'.
Looking at the respiratory resistance again, it determines whether you can wear it: many high-end masks can make people feel dizzy and stuffy. Fangdun's half face mask (1105 series) has a nominal inhalation resistance of about 20 Pa and an exhalation resistance of less than 50 Pa, and some models with resistance reducing valves can lower the exhalation resistance to below 35 Pa. The actual feeling is that wearing it while working will not make you feel like someone is pinching your nose, the exhalation valve will quickly release hot and humid air, and there will be less fogging of the glasses.
Finally, let's take a look at the fit and material: the cover is made of food grade liquid silicone, weighing approximately 125 grams. The advantage of silicone is that it is soft and can follow the shape of the face, making it less likely for the nose bridge and jaw to leak air. After wearing it, remember to do a negative pressure self check: block the air intake with your palm and inhale, the cover should slightly collapse without any air leakage sound, then it is considered qualified for wearing.
To be honest, filter cotton is a consumable and cannot be washed with water. Once the electrostatic layer is washed, it becomes useless. When you feel difficulty breathing or the filter cotton becomes noticeably dirty and discolored, simply replace it with a new one. Just wipe the main body of the mask with a neutral damp cloth, don't spray alcohol forcefully.
If you only occasionally sweep the dust, the KN95 disposable model is sufficient; If you are staying in a dusty environment for a long time, simply using KN100 half face mask with filter cotton will actually result in lower daily costs. Choose according to the scene, don't blindly stack levels, and don't let your lungs suffer just to save a few dollars.
