These are not surgical masks or a form of approved medical-grade PPE.  They have not been formally tested or approved by any relevant institution.  Given that we have limited access to research facilities and materials, and few opportunities to conduct formal testing, we are starting with materials that are known to be safe and able to withstand repeated washing.  Each pattern has gone through a rigorous iteration process to streamline construction and clarify instructions, but this optimization is an ongoing process.  We make no claims about the efficacy of our designs, particularly when constructed at home.