2. Sterile and non-sterile medical masks on the market are actually legally sold. There is no problem with defective products, but they should be selected according to different application scenarios. We know that sterile masks must be used in medical environment to prevent patients from being infected by bacteria. These medical environments mainly include ICU, operating room and other places that need strict control of microbial environment. On the contrary, in our daily use, we don't really need this kind of sterile mask. You only need to wear non-sterile masks to meet the requirements of safety protection, because their protection level is 654.38+ 10,000, which can meet the safety of use.