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 in public, 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 really make much sense to me. Furthermore, I’d like to point out solutions for a more responsible, safe and sustainable use of medical masks. One of these solutions could be wearing a cloth cover over medical masks, or double masking. … ➔