In Germany, the wearing of medical masks, i.e. FFP2 or surgical masks, became mandatory yesterday. Since I don’t think anyone will check certifications, this means that everything except cloth masks is allowed. I’d like to explain how masks work, how filter and fit determine their efficiency, and why a cloth mask ban doesn’t make much sense to me. Furthermore, I’d like to point out solutions for a more responsible, safe and sustainable use of medical masks. … ➔