Do You Know How to Define Whether A Mask Is Qualified or Not
As we all know a face mask is a tool for personal health protection when people are in danger of germ infection because of its filter function. Therefore filter function will be the core of a mask. Usually Melt-blown fabric in a mask offer this function so if you want to know whether a mask is qualified or not, focus on the melt-blown fabric and checking its filtering function and no one can make fool of you.