What are the challenges faced by the KN95 face mask factories?

We all know that these masks are Chinese equivalent. And these masks are responsible for filtering 95% of aerosol particles. Using the KN95 masks made by these KN95 mask factories is perfectly safe. But this article will tell you a different story about it: Frontline workers at risk ECRI a non-profit organization, responsible for the health and safety of people tells us that doctors and nurses are using KN95s that are not filtering 95 percent of particulates. And the team at the ECRI noted that by testing around 200masks, they came to know that these masks are not suitable at high-risk times as it does not filter 95%partiles as claimed. And watching the result, ECRI chose to raise the alarm and alert the public and healthcare professionals. According to Dr Marcus Schabacker, president and chief executive officer at ECRI , "Because of the terrible situation, U.S. hospitals bought hundreds of thousands of masks made in China over the past six months, and we're finding that man...