1. Try to buy masks that are packaged and have the "LA" (Labour Protection) logo on the package or have both the "LA" and "QS" marks.

2. Pay attention to the product identification when purchasing, and check whether the product name, production date, factory name, factory address, shelf life, product instruction manual, etc. are clearly marked.

3. The filter material used in masks has generally undergone a very complicated process. It is a one-time product and should not be washed.

4. Because peoples face shapes are different, a designed mask may not be suitable for everyone. Some people wear tight fits, and some people may not be able to fit tightly. Therefore, before using a certain type of mask for the first time, it is best to try it according to the instructions. wore. Even if factors such as the use environment and product characteristics are considered, the product may be inefficient or even ineffective because it is not suitable for the user.